JP6739915B2 - Laser amplification system - Google Patents

Description

The present invention relates to a laser amplification system, and more particularly to a laser amplification system that disperses a heat load acting on a laser gain medium by changing the position of a reflection spot of a laser.

In recent years, research and development of an active mirror type solid-state laser system (reflection type solid-state laser system) have been conducted. In the active mirror type solid-state laser system, a part of the disk or plate-shaped laser gain medium is covered with a reflective film. The laser light is introduced into the laser gain medium from a surface different from the surface covered with the reflective film, reflected by the reflective film, and output to the outside of the laser gain medium from the surface different from the surface covered with the reflective film. ..

By the way, in the fields of laser processing and defense, the required laser output tends to increase, and the thermal load acting on the laser gain medium tends to increase.

As a related technique, Patent Document 1 describes a solid-state laser device. The solid-state laser device described in Patent Document 1 includes a solid-state laser gain medium, a coolant that cools the solid-state laser gain medium, and a coolant container that contains the coolant. The solid-state laser gain medium is placed in the opening of the refrigerant container. By pressing the solid-state laser gain medium toward the inner surface of the cooling container, the opening of the refrigerant container is closed by the solid-state laser gain medium. The solid-state laser gain medium is cooled by bringing the laser reflection surface into contact with the coolant.

Patent Document 2 describes a laser oscillator and a laser amplifier. The laser oscillator and the laser amplifier described in Patent Document 2 each include an optical medium and a laser gain medium joined to the optical medium. Cooling means is provided around the laser gain medium. The cooling means cools the back side of the laser gain medium.

Patent Document 3 describes a laser wavelength conversion device. The laser wavelength conversion device described in Patent Document 3 has a laser resonator, a nonlinear optical crystal arranged in the laser resonator, and a parallel plate transmission for laser beam optical path shift arranged upstream of the nonlinear optical crystal. A plate and a vibration mechanism that vibrates the transmission plate are provided. The nonlinear optical crystal is a crystal that generates a harmonic beam from an incident laser beam. The optical path of the laser beam is shifted by vibrating the parallel plate transmission plate for shifting the optical path of the laser beam. Due to the optical path shift of the laser beam, the passage path of the laser beam in the nonlinear optical crystal changes. The temperature rise of the nonlinear optical crystal is suppressed by the change of the passage.

Patent Document 4 describes a harmonic laser device. The harmonic laser device described in Patent Document 4 includes a pumping semiconductor laser, a condenser lens, a reflection mirror, a solid-state laser medium, a nonlinear optical crystal, and an output mirror. The harmonic laser device is a moving mechanism that moves the position of the nonlinear optical crystal in a direction perpendicular to the optical axis of the laser light, or a moving mechanism that changes the passing position of the laser light on the nonlinear optical crystal in conjunction with laser irradiation. It includes an optical element with a mechanism. By using the moving mechanism or the optical element with the moving mechanism, the passage path of the laser beam in the nonlinear optical crystal changes. The temperature rise of the nonlinear optical crystal is suppressed by the change of the passage.

Patent Document 5 describes a solid-state laser device. The solid-state laser device described in Patent Document 5 includes a semiconductor laser light source, a rod lens, a VBG, a ball lens, a mirror, a solid-state laser crystal, a wavelength conversion element, and a concave mirror. The concave mirror is arranged so as to be tilted from the optical axis of the laser. By arranging the concave mirror at an angle from the optical axis, the laser light transmission region in the solid-state laser crystal or the wavelength conversion element is expanded. The expansion of the laser light transmission region suppresses the temperature rise of the solid-state laser crystal and the wavelength conversion element.

Japanese Patent No. 5424320 Japanese Patent No. 5330801 JP-A-7-22686 JP, 2004-22946, A JP, 2009-259854, A

An object of the present invention is to provide a laser amplification system that disperses the heat load acting on the laser gain medium by changing the position of the laser reflection spot. The dispersion of the heat load suppresses the temperature rise of the laser gain medium.

These and other objects and benefits of the present invention can be easily confirmed by the following description and the accompanying drawings.

The means for solving the problems will be described below by using the numbers and symbols used in the embodiments for carrying out the invention. These numbers and reference numerals are added in parentheses as a reference in order to show an example of the correspondence between the description of the claims and the modes for carrying out the invention. Therefore, the description in parentheses should not be construed as limiting the scope of the claims.

A laser amplification system according to some embodiments receives a seed light (A) and a pump light (B), and outputs the seed light (A) and the pump light (B) as a coaxial light (C). An optical element (40; 40'), which receives the coaxial light (C), amplifies the seed light (A) using the excitation light (B), and obtains amplification by amplification of the seed light (A). An amplifier (60;60':60'') for outputting light (M) is disposed between the first optical element (40;40') and the amplifier (60;60':60''). , An input side optical system (50) that receives the coaxial light (C) from the first optical element (40; 40′) and supplies the coaxial light (C) to the amplifier (60; 60′:60″). 50'; 50''; 50''') and the input side optical system (50; 50'; 50''; 50''') to drive the amplifier (C) for the coaxial light (C). 60; 60': 60''), a drive mechanism (80; 80'; 80'') for changing the incident position (65) or the incident direction (D), and the drive mechanism (80; 80'; 80'). ') and a control device (90) for controlling The amplifier (60; 60′:60″) introduces the coaxial light (C) into the first laser gain medium (62) for amplifying the seed light (A) and the coaxial light (C). A first reflective layer (67) that reflects light. The control device (90) controls the drive mechanism (80; 80 ′; 80 ″) to change the incident position (65) or the incident direction (D), and thereby the first reflective layer. The position of the reflection spot (68) of the coaxial light (C) at (67) is moved.

In the above laser amplification system, the input side optical system (50; 50''; 50''') includes a first mirror (50; 50''; 50-1) that reflects the coaxial light (C). You can leave. The drive mechanism (80;80'') includes a first drive mechanism (80;80'';80-1) that swings or rotates the first mirror (50;50'';50-1). You can leave.

The laser amplification system according to claim 2, wherein
In the laser amplification system, the control device (90) causes the first mirror (50; 50''; 50-1) to swing or rotate around a first axis (X; X1; AX1). You may control the said 1st drive mechanism (80;80'';80-1). When the first mirror (50; 50''; 50-1) swings or rotates around the first axis (X; X1; AX1), the reflection spot (68) becomes the first reflection. It may move over the layer (67).

In the above laser amplification system, the control device (90) causes the first mirror (50″) to swing or rotate around a second axis (AX2) different from the first axis (AX1). Alternatively, the first drive mechanism (80″) may be controlled. The first mirror (50″) swings or rotates about the first axis (AX1) and also swings or rotates about the second axis (AX2), whereby the reflection spot (68). May move two-dimensionally on the first reflective layer (67).

In the laser amplification system, the input side optical system is disposed between the first mirror (50-1) and the amplifier (60; 60′:60″), and the first mirror (50-1). ), and may include the 2nd mirror (50-2) which receives the said coaxial light (C) from, and reflects the said coaxial light (C). Further, the drive mechanism (80) may include a second drive mechanism (80-2) that swings or rotates the second mirror (50-2). Further, the control device (90) may execute a parallel incidence mode in which the incident position (65) is changed while the incident direction (D) is fixed.

In the laser amplification system, an output side optical system (55; 55') that receives the amplified light (M), collects the amplified light (M), and outputs the amplified light (M) in a fixed direction. May be further included. The output side optical system (55; 55') may output the amplified light (M) in the fixed direction (F) regardless of the movement of the position of the reflection spot (68).

In the above laser amplification system, the output side optical system (55') may be a fixed type condensing optical system.

In the laser amplification system, the input side optical element forming the input side optical system (50′″) and the output side optical element forming the output side optical system (55) are arranged symmetrically to each other. May be.

In the laser amplification system, the amplified light (M) from the amplifier (60; 60′:60″) is incident, and a third mirror (55-3) that reflects the amplified light (M); The amplified light (M) from the third mirror (55-3) is incident, and the fourth mirror (55-4) that reflects the amplified light (M) and the third mirror (55-3) are shaken. A third drive mechanism (85-3) that moves or rotates and a fourth drive mechanism (85-4) that swings or rotates the fourth mirror (55-4) may be further provided. The third mirror (55-3) and the fourth mirror (55-4) may form the output side optical system (55).

In the laser amplification system, the amplifier (60′; 60″) receives the coaxial light (C) from the first laser gain medium (62) and amplifies the seed light (A). A laser gain medium (62-2) and a second reflection layer (67-2) that reflects the coaxial light (C) may be provided.

The laser amplification system may further include a cooling mechanism (70) for cooling the first laser gain medium (62).

In the above laser amplification system, the cooling mechanism (70) may include a heat sink (70) disposed in contact with the first reflective layer (67).

In the above laser amplification system, the cooling mechanism (70) may include a coolant channel (72) and a coolant supply mechanism (74) that supplies a coolant to the coolant channel (72).

In the above laser amplification system, the refrigerant flow path (72) may include a refrigerant discharge port (101A, 101B) for supplying the refrigerant toward the optical element. The coolant may wash the optical element.

In the above laser amplification system, a casing (100) surrounding the amplifier (60; 60′:60″) and the amplified light (M) from the inside of the casing (100) to the casing (100). An output window (110) for outputting to the outside may be further provided. The optical component that is cleaned may be the output window (110).

According to the present invention, it is possible to provide a laser amplification system that disperses the heat load acting on the laser gain medium by changing the position of the reflection spot of the laser.

FIG. 1 is a diagram schematically showing a laser amplifier in a comparative example. The upper drawing of FIG. 1 is a side view, and the lower drawing of FIG. 1 is a bottom view. FIG. 2 is a diagram schematically showing a laser resonator in another comparative example. FIG. 3A is a plan view schematically showing the laser amplification system according to the first embodiment. FIG. 3B is a side view schematically showing the laser amplification system of the first embodiment. FIG. 3C is a plan view schematically showing the laser amplification system of the first modified example of the first embodiment. FIG. 3D is a plan view schematically showing the laser amplification system of the second modified example of the first embodiment. FIG. 3E is a plan view schematically showing a laser amplification system of a third modified example of the first embodiment. FIG. 3F is a side view schematically showing a laser amplification system of a third modified example of the first embodiment. FIG. 3G is a plan view schematically showing the laser amplification system of the fourth modified example of the first embodiment. FIG. 3H is a side view schematically showing the laser amplification system of the fourth modified example of the first embodiment. FIG. 3I is a plan view schematically showing the laser amplification system of the fourth modified example of the first embodiment. FIG. 3J is a side view schematically showing a laser amplification system of a fourth modified example of the first embodiment. FIG. 3K is a plan view schematically showing the laser amplification system of the fifth modified example of the first embodiment. FIG. 3L is a plan view schematically showing the laser amplification system of the fifth modified example of the first embodiment. FIG. 3M is a plan view schematically showing the laser amplification system of the fifth modified example of the first embodiment. FIG. 4A is a plan view schematically showing the laser amplification system of the second embodiment. FIG. 4B is a side view schematically showing the laser amplification system of the second embodiment. FIG. 4C is a diagram schematically showing an example of the parallel incidence mode. FIG. 4D is a plan view schematically showing the laser amplification system of the first modified example of the second embodiment. FIG. 4E is a side view schematically showing the laser amplification system of the first modified example of the second embodiment. FIG. 4F is a plan view schematically showing a laser amplification system of a second modification of the second embodiment. FIG. 5A is a plan view schematically showing the laser amplification system of the third embodiment. FIG. 5B is a side view schematically showing the laser amplification system of the third embodiment. FIG. 5C is a plan view schematically showing the laser amplification system of the first modified example of the third embodiment. FIG. 5D is a side view schematically showing the laser amplification system of the first modified example of the third embodiment. FIG. 5E is a plan view schematically showing the laser amplification system of the second modified example of the third embodiment. FIG. 5F is a side view schematically showing the laser amplification system of the second modified example of the third embodiment. FIG. 5G is a plan view schematically showing the laser amplification system of the third modified example of the third embodiment. FIG. 6A is a plan view schematically showing the laser amplification system of the fourth embodiment. FIG. 6B is a sectional view schematically showing the laser amplification system of the fourth embodiment.

Hereinafter, a laser amplification system according to an embodiment will be described with reference to the accompanying drawings.

(Matters recognized by the inventor)
Matters recognized by the inventor will be described with reference to FIGS. 1 and 2.

FIG. 1 is a diagram schematically showing a laser amplifier 1 in a comparative example. The upper drawing of FIG. 1 is a side view, and the lower drawing of FIG. 1 is a bottom view.

In FIG. 1, the laser amplifier 1 includes a laser gain medium 2 and a reflective film 3. The seed light 4 is introduced into the laser gain medium 2 and reflected by the reflection film 3 at the position of the reflection spot 6. The pumping light 5 is introduced into the laser gain medium 2 and reflected by the reflecting film 3 at the position of the reflecting spot 6. Part of the seed light 4 and part of the pump light 5 are absorbed by the laser gain medium 2 and converted into heat.

By the way, as in the example shown in FIG. 1, in the laser amplifier 1, the seed light 4 and the pump light 5 need to be applied to the same location in the laser gain medium 2. Therefore, in general, the optical path of the seed light 4 and the optical path of the excitation light 5 are fixed and do not change with time.

Therefore, the thermal load (temperature rise) of the laser gain medium 2 is large in the optical path of the seed light 4 and the optical path of the pumping light 5. In particular, the heat load (temperature rise) becomes large in the peripheral area of the reflection spot 6.

FIG. 2 is a diagram schematically showing a laser resonator 10 in another comparative example.

The laser resonator 10 includes a resonator mirror 11, a laser gain medium 13, a parallel plate transmission plate 14, a nonlinear optical crystal 15, a resonator mirror 12, and a laser pumping lamp 18. The resonator mirrors 11 and 12 have a high reflectance with respect to the laser light of the frequency f and a high transmittance with respect to the laser light of the frequency 2f. The laser gain medium 13 generates laser light having a frequency f. The parallel plate transmission plate 14 changes the optical path of the laser light by using the refraction phenomenon of light. The nonlinear optical crystal 15 converts the laser light of frequency f into the laser light of frequency 2f. The laser pumping lamp 18 pumps the laser gain medium 13.

The laser light of the frequency f generated in the laser gain medium 13 by using the laser excitation lamp 18 is introduced into the parallel plate transmission plate 14 and passes through the parallel plate transmission plate 14. When the parallel plate transmission plate 14 is in the first position shown by the broken line in FIG. 2, the laser light passes through the optical path 16 and the nonlinear optical crystal 15. On the other hand, when the parallel plate transmission plate 14 is in the second position shown by the solid line in FIG. 2, the laser light passes through the optical path 17 and the nonlinear optical crystal 15. The laser light passing through the nonlinear optical crystal 15 through the optical path 16 or the optical path 17 is converted into laser light having a frequency of 2f. Then, the laser light of frequency 2f passes through the resonator mirror 12 and is extracted toward the outside of the laser resonator 10.

In the example shown in FIG. 2, since the optical path of the laser light passing through the nonlinear optical crystal 15 is changed (between the optical path 16 and the optical path 17), the temperature rise of the nonlinear optical crystal 15 is suppressed. However, the example shown in FIG. 2 shows the temperature rise suppressing technique applied to the laser resonator, and does not show the temperature rise suppressing technique applicable to the laser amplifier. For example, in the case of a laser amplifier, it is necessary to introduce laser light (seed light and pumping light) having different frequencies into a laser gain medium so that the same location is irradiated with the laser light. However, the example described in FIG. 2 is not suitable for such a case. For example, in the optical path change using the swing of the parallel plate transmission plate, two lights having different frequencies may be separated from each other, that is, the coaxial light may not be maintained.

Further, the above-mentioned Patent Document 4 also fails to show a temperature rise suppressing technique applicable to the laser amplifier. For example, Patent Document 4 describes the shift of the optical axis due to the movement of the optical element 22 with a moving mechanism. When the technique described in Patent Document 4 is applied to an amplifier, there is a possibility that coaxial light may not be maintained due to the shift of the optical axis.

Note that FIG. 1 and FIG. 2 are diagrams for explaining the matters recognized by the inventor, and do not show known problems or the like.

(First embodiment)
A laser amplification system 30 according to the first embodiment will be described with reference to FIGS. 3A and 3B. 3A is a plan view schematically showing the laser amplification system 30, and FIG. 3B is a side view schematically showing the laser amplification system 30 (a side view when FIG. 3A is viewed along the arrow T direction). .. Note that in FIG. 3B, in order to avoid complication of the drawing, components other than the input side optical system 50 and the amplifier 60 are not shown.

The laser amplification system 30 includes a first optical element 40, an input side optical system 50, an amplifier 60, a drive mechanism 80, and a control device 90. The laser amplification system 30 may include at least one of the seed light source 98 and the pump light source 99.

(light source)
The seed light source 98 is a light source of the seed light A to be amplified. The seed light A has a wavelength λ1. The seed light A is incident on the first optical element 40. Note that one or a plurality of optical elements may be arranged between the seed light source 98 and the first optical element 40.

The pumping light source 99 is a light source of pumping light B that pumps a first laser gain medium 62 described later. The excitation light B has a wavelength λ2 different from the wavelength λ1 of the seed light A. The wavelength λ2 of the excitation light may be larger than the wavelength λ1 of the seed light or smaller than the wavelength λ1 of the seed light. The excitation light B is incident on the first optical element 40. Note that one or a plurality of optical elements may be arranged between the excitation light source 99 and the first optical element 40.

(First optical element)
The first optical element 40 receives the seed light A and the excitation light B, and outputs the seed light A and the excitation light B as the coaxial light C. In the present specification, “coaxial” means that the traveling direction of the seed light A is the same as the traveling direction of the excitation light B (the traveling direction of the seed light A is substantially the same as the traveling direction of the excitation light B. (Including a certain case) and at least a part of the seed light A and at least a part of the excitation light B are overlapped with each other. That is, the coaxial light C includes the seed light A and the excitation light B, and the traveling direction of the seed light A forming the coaxial light C and the traveling direction of the excitation light B forming the coaxial light C are the same (substantially The same), and at least a part of the seed light A forming the coaxial light C and at least a part of the excitation light B forming the coaxial light C overlap each other. In the coaxial light C, the optical path of the excitation light B may completely include the optical path of the seed light A. For example, the diameter of the excitation light B in the cross section perpendicular to the traveling direction of the excitation light B may be larger than the diameter of the seed light A in the cross section perpendicular to the traveling direction of the seed light A. In the coaxial light C, the central axis of the excitation light B and the central axis of the seed light A may be aligned with each other, or may be offset from each other to some extent.

The first optical element 40 is, for example, a dichroic mirror. In the example illustrated in FIG. 3A, the dichroic mirror (first optical element 40) is a mirror that transmits the seed light A having the wavelength λ1 and reflects the excitation light B having the wavelength λ2. Alternatively, the dichroic mirror (first optical element 40) may be a mirror that reflects the seed light A having the wavelength λ1 and transmits the excitation light B having the wavelength λ2. In the latter case, in FIG. 3A, the position of the seed light source 98 may be changed to the position of the excitation light source 99 in FIG. 3A, and the position of the excitation light source 99 may be changed to the position of the seed light source 98 in FIG. 3A.

(Input side optical system)
The input side optical system 50 is an optical system arranged between the first optical element 40 and the amplifier 60. The input side optical system 50 receives the coaxial light C from the first optical element 40. Further, the input side optical system 50 supplies the coaxial light C to the amplifier 60.

In the example illustrated in FIGS. 3A and 3B, the input side optical system 50 includes a polygon mirror (first polygon mirror). In the polygon mirror, for example, the mirror is arranged on each side surface of the regular polygonal column. As the polygon mirror rotates about the X axis, the traveling direction of the coaxial light C reflected by the polygon mirror changes. For example, in FIG. 3B, the optical path C1 shows the optical path of the coaxial light C when the polygon mirror is in the first position, and the optical path C2 shows the optical path of the coaxial light C when the polygon mirror is in the second position. Show.

In the example shown in FIG. 3A, the rotation of the polygon mirror is performed by the drive mechanism 80 (first drive mechanism). In the example shown in FIG. 3A, the drive mechanism 80 includes a motor 81 and an output shaft 82, and the output shaft 82 and the polygon mirror are mechanically connected. An appropriate power transmission mechanism may be arranged between the motor 81 and the polygon mirror.

The drive mechanism 80 is driven based on a command signal (for example, an electric signal) from the control device 90. In the example shown in FIG. 3A, the control device 90 and the drive mechanism 80 are electrically connected, and the drive mechanism 80 is based on a command signal from the control device 90 and the polygon mirror (input side optical system 50). To drive. The drive mechanism 80 rotates the polygon mirror, for example, around the X axis at a constant angular velocity.

The input side optical system 50 may include other optical elements in addition to the polygon mirror.

(amplifier)
The amplifier 60 receives the coaxial light C from the input side optical system 50. The amplifier 60 includes a first laser gain medium 62 and a first reflective layer 67.

The first laser gain medium 62 is excited by the excitation light B into a high energy state. Further, the seed light A passes through the first laser gain medium 62 in the excited state, so that energy is stimulated and emitted. As a result, the seed light A is amplified. The amplified seed light A is output as amplified light M from the amplifier 60. In this specification, the laser light output from the amplifier is called “amplified light”.

A solid laser gain medium may be used as the first laser gain medium 62. When a solid-state laser gain medium is used as the first laser gain medium 62, for example, yttrium aluminum garnet (YAG) containing ytterbium trivalent ions (Yb ³⁺ ) may be selected as the solid-state laser gain medium. Alternatively, a liquid laser gain medium may be used as the first laser gain medium 62. When a liquid laser gain medium is used as the first laser gain medium 62, for example, a liquid in which a fluorescent organic dye (eg, oxazine-based dye) is melted in a solvent (eg, alcohol) is selected as the liquid laser gain medium. May be done.

The first laser gain medium 62 includes a surface 63 on the side on which the coaxial light C is incident, and a surface 64 arranged in contact with the first reflective layer 67.

The first reflective layer 67 is arranged in contact with the surface 64 of the first laser gain medium 62. The first reflective layer 67 reflects the coaxial light C. The first reflective layer 67 may be a reflective film, a reflective film, or a reflective coating. The first reflective layer 67 is, for example, a dielectric multilayer film.

As understood from FIGS. 3A and 3B, the incident position 65 or the incident direction of the coaxial light C to the amplifier 60 (first laser gain medium 62) is driven by driving the polygon mirror (the input side optical system 50). D is changed. In the example shown in FIGS. 3A and 3B, both the incident position 65 and the incident direction D are changed. The incident direction D is inclined with respect to the surface 63 (and the first reflective layer 67). In other words, the incident angle with respect to the surface 63 in the incident direction D is, for example, larger than 0 degrees and smaller than 90 degrees.

By changing the incident position 65 or the incident direction D, the position of the reflection spot 68 on the first reflective layer 67 moves. In the example shown in FIG. 3B, the reflection spot 68 corresponding to the optical path C1 is the reflection spot 68D1, and the reflection spot 68 corresponding to the optical path C2 is the reflection spot 68D2. When the polygon mirror is continuously rotated about the X axis in the R direction (see FIG. 3A), the position of the reflection spot 68 is changed from the position indicated by reference numeral 68D1 to the position indicated by reference numeral 68D2. It moves continuously (see the arrow labeled E in FIG. 3B). Then, when the coaxial light C passes through the corner 51 (see FIG. 3B) of the polygon mirror due to the rotation of the polygon mirror, the position of the reflection spot 68 is indicated by the reference numeral 68D1 from the position indicated by the reference numeral 68D2. Move to position discontinuously.

The rotation of the polygon mirror about the X axis may be continuous rotation or intermittent rotation. When the polygon mirror is rotated intermittently, the position of the reflection spot 68 is intermittently moved from the position indicated by reference numeral 68D1 to the position indicated by reference numeral 68D2. However, in order to obtain a more uniform amplified light M, it is preferable to continuously rotate the polygon mirror rather than intermittently rotate the polygon mirror.

In the first embodiment, the input side optical system 50 is driven during the operation of the laser amplification system 30 (in other words, during the output of the amplified light M). More specifically, in the first embodiment, the position or the angle of an optical element (for example, a polygon mirror or the like) forming the input side optical system 50 changes during the operation of the laser amplification system 30 (for example, the position). Or the angle changes periodically). Then, by driving the input side optical system 50, the position of the reflection spot 68 of the coaxial light C on the first reflection layer 67 moves. As a result, the heat load acting on the first laser gain medium 62 is dispersed.

Further, in the first embodiment, the input side optical system 50 is composed of a polygon mirror. For this reason, for example, the axis shift between the seed light A and the excitation light B is suppressed as compared with the case of using the swing of the parallel plate transmission plate. As a result, the incident position (or incident direction) of the seed light A forming the coaxial light C on the first laser gain medium and the incident position of the pump light B forming the coaxial light C on the first laser gain medium (or Deviation from the incident direction) is suppressed.

Further, when a polygon mirror is adopted as the input side optical system 50, the position of the reflection spot 68 changes periodically as shown in FIG. 3B. More specifically, the position of the reflection spot moves from the position indicated by reference numeral 68D1 toward the position indicated by reference numeral 68D2, and the movement is periodically repeated. On the other hand, when a swinging mirror is adopted as the input side optical system 50, the position of the reflection spot 68 is periodically between the position indicated by reference numeral 68D1 and the position indicated by reference numeral 68D2. Move back and forth. In the latter example (an example of an oscillating mirror), the intermediate portion between the position indicated by reference numeral 68D1 and the position indicated by reference numeral 68D2 corresponds to the position indicated by reference numeral 68D1 (end portion) or reference numeral. It is easier to be heated by the coaxial light than the portion (end portion) corresponding to the position indicated by 68D2. On the other hand, in the former example (example of polygon mirror), the heating of the intermediate portion by the coaxial light and the heating of the end portion by the coaxial light are likely to be about the same. Therefore, the former example (example of polygon mirror) is more advantageous than the latter example (example of oscillating mirror) from the viewpoint of obtaining uniform amplified light.

(First Modification of First Embodiment)
FIG. 3C is a plan view schematically showing a laser amplification system 30A of a first modified example of the first embodiment. In addition, in the laser amplification system 30A of the first modified example, components having the same functions as the components of the laser amplification system 30 of the first embodiment are given the same drawing numbers, and repeated description is omitted.

In the example shown in FIG. 3C, the first optical element 40 of FIG. 3A is replaced with the first optical element 40'. The other configurations in FIG. 3C are similar to the configurations in FIG. 3A.

The first optical element 40' is, for example, a diffraction grating. The first optical element 40' receives the seed light A and the excitation light B, and outputs the seed light A and the excitation light B as the coaxial light C. The seed light A of wavelength λ1 and the excitation light B of wavelength λ2 are incident on the first optical element 40' (diffraction grating) at different incident angles. The coaxial light C is output from the first optical element 40' (diffraction grating). In the example illustrated in FIG. 3C, the first optical element 40' is a reflective diffraction grating, but a transmissive diffraction grating may be alternatively used.

(Second Modification of First Embodiment)
FIG. 3D is a plan view schematically showing a laser amplification system 30B of the second modification example of the first embodiment. In addition, in the laser amplification system 30B of the second modified example, the components having the same functions as the components of the laser amplification system 30 of the first embodiment are given the same drawing numbers, and repeated description is omitted.

In the example shown in FIG. 3D, the input side optical system 50 in FIG. 3A is replaced with the input side optical system 50', and the drive mechanism 80 is replaced with the drive mechanism 80' (first drive mechanism). Other configurations in FIG. 3D are similar to those in FIG. 3A.

The input side optical system 50 ′ is an optical system arranged between the first optical element 40 and the amplifier 60. The input side optical system 50 ′ receives the coaxial light C from the first optical element 40. Further, the input side optical system 50 ′ supplies the coaxial light C to the amplifier 60. In the example shown in FIG. 3D, the input side optical system 50' includes an optical fiber. The exit end of the optical fiber is connected to a drive mechanism 80' (for example, a manipulator). By the drive of the drive mechanism 80', the end portion on the emitting side of the optical fiber moves continuously or intermittently. When the optical fiber is in the position shown by the solid line in FIG. 3D, the coaxial light C travels along the optical path C1. Then, the coaxial light C is reflected at the reflection spot 68D1. On the other hand, when the optical fiber is in the position shown by the broken line in FIG. 3D, the coaxial light C travels along the optical path C2. Then, the coaxial light C is reflected at the reflection spot 68D2.

In the second modification shown in FIG. 3D, the position of the reflection spot 68 of the coaxial light C on the first reflection layer 67 moves. As a result, the heat load acting on the first laser gain medium 62 is dispersed. Further, in the second modified example, the input side optical system 50' is configured by an optical fiber. For this reason, for example, the axis shift between the seed light A and the excitation light B is suppressed as compared with the case of using the swing of the parallel plate transmission plate.

It is also possible to use a prism as the input side optical system. However, when the input side optical system includes an optical element (prism or the like) that uses refraction, the seed light A and the excitation light B may be separated by refraction. Therefore, it is preferable that the input-side optical system does not include an optical element that uses refraction, unless the difference between the wavelength λ1 of the seed light A and the wavelength λ2 of the excitation light B is not large.

(Third Modification of First Embodiment)
FIG. 3E is a plan view schematically showing a laser amplification system 30C of a third modified example of the first embodiment. Further, FIG. 3F is a side view schematically showing a laser amplification system 30C according to a third modified example of the first embodiment. In addition, in the laser amplification system 30C of the third modified example, the components having the same functions as the components of the laser amplification system 30 of the first embodiment are given the same drawing numbers, and the repeated description is omitted.

In the example described in FIGS. 3E and 3F, the amplifier 60 of FIGS. 3A and 3B is replaced by an amplifier 60'. Other configurations in FIGS. 3E and 3F are similar to those in FIGS. 3A and 3B.

The amplifier 60' includes a first-stage amplification unit 60-1 and a second-stage amplification unit 60-2. The first-stage amplification unit 60-1 includes a first laser gain medium 62 and a first reflection layer 67. The first laser gain medium 62 and the first reflective layer 67 are the same as the first laser gain medium 62 and the first reflective layer 67 described in FIGS. 3A and 3B, respectively. Therefore, repeated description of the first laser gain medium 62 and the first reflective layer 67 is omitted.

The second-stage amplification unit 60-2 includes a second laser gain medium 62-2 and a second reflection layer 67-2. The second laser gain medium 62-2 is excited by the excitation light B into a high energy state. Further, the seed light A passes through the second laser gain medium 62-2 in the excited state, so that energy is stimulated and emitted. As a result, the seed light A is amplified. The material of the second laser gain medium 62-2 may be the same as or different from the material of the first laser gain medium 62. In the example illustrated in FIGS. 3E and 3F, the second laser gain medium 62-2 is arranged apart from the first laser gain medium 62.

The second laser gain medium 62-2 includes a surface 63-2 on the side on which the coaxial light C is incident, and a surface 64-2 arranged in contact with the second reflective layer 67-2.

The second reflective layer 67-2 is arranged in contact with the surface 64-2 of the second laser gain medium 62-2. The second reflective layer 67-2 reflects the coaxial light C. The material of the second reflective layer 67-2 may be the same as or different from the material of the first reflective layer 67.

As understood from FIGS. 3E and 3F, the incident position 65-2 or the incident direction D′ of the coaxial light C on the second laser gain medium 62-2 is changed by driving the input side optical system 50. To be done. In the example shown in FIGS. 3E and 3F, both the incident position 65-2 and the incident direction D′ are changed.

Further, the position of the reflection spot 68-2 on the second reflection layer 67-2 moves by changing the incidence position 65-2 or the incidence direction D′. In the example illustrated in FIG. 3F, the reflection spot 68-2 corresponding to the optical path C1 is the reflection spot 68D1-2, and the reflection spot 68-2 corresponding to the optical path C2 is the reflection spot 68D2-2. When the input side optical system 50 is continuously rotated around the X axis in the R direction, the position of the reflection spot 68-2 is changed from the position indicated by reference numeral 68D1-2 to the position indicated by reference numeral 68D2-2. It continuously moves towards (see the arrow labeled E'in FIG. 3F). Then, when the coaxial light C passes through the corner 51 of the polygon mirror due to the rotation of the input side optical system 50, the position of the reflection spot 68-2 is changed from the position indicated by the reference numeral 68D2-2 to the reference numeral 68D1-2. Move discontinuously to the position indicated by.

In the third modification of the first embodiment, the position of the reflection spot 68-2 of the coaxial light C on the second reflection layer 67-2 moves. As a result, the heat load acting on the second laser gain medium 62-2 is dispersed. Further, in the third modified example, the amplifier includes the first-stage amplification unit 60-1 and the second-stage amplification unit 60-2. Therefore, in the third modification, a laser amplification system having a higher amplification factor of seed light can be realized as compared with the examples described in FIGS. 3A and 3B.

Although the number of amplification units is two in the example shown in FIGS. 3E and 3F, the number of amplification units may be three or more. In the examples shown in FIGS. 3E and 3F, the input side optical system 50 is composed of a polygon mirror. Alternatively, the input side optical system 50 may be configured by the optical fiber shown in FIG. 3D or a mirror other than a polygon mirror (for example, a galvano mirror, a piezo mirror, a MEMS mirror).

(Fourth Modification of First Embodiment)
FIG. 3G is a plan view schematically showing the laser amplification system 30D of the fourth modified example of the first embodiment. Further, FIG. 3H is a side view schematically showing a laser amplification system 30D of a fourth modified example of the first embodiment. In addition, in the laser amplification system 30D of the fourth modified example, the components having the same functions as the components of the laser amplification system 30 of the first embodiment are designated by the same reference numerals, and the repeated description will be omitted.

In the example shown in FIGS. 3G and 3H, the input side optical system 50 of FIGS. 3A and 3B is replaced with the input side optical system 50″, and the drive mechanism 80 of FIGS. 3A and 3B is replaced with the drive mechanism 80′. '(First drive mechanism). Other configurations in FIGS. 3G and 3H are similar to those in FIGS. 3A and 3B.

The input side optical system 50 ″ is an optical system arranged between the first optical element 40 and the amplifier 60. The input side optical system 50 ″ receives the coaxial light C from the first optical element 40. The input side optical system 50 ″ also supplies the coaxial light C to the amplifier 60. In the example illustrated in FIGS. 3G and 3H, the input side optical system 50 ″ includes a mirror (first mirror). The mirror is, for example, a galvano mirror (a mirror of a type in which the mirror is swung about an axis), a piezo mirror (a mirror that is oscillated by a piezo element), or a MEMS mirror (a mirror that is driven by a Micro Electro Mechanical System). is there.

The mirror (input side optical system 50″) described in FIGS. 3G and 3H is connected to the drive mechanism 80″ and driven by the drive mechanism 80″. When the mirror is a piezo mirror, the drive mechanism 80″ includes a piezo element. If the mirror is a MEMS mirror, the drive mechanism 80 ″ includes a MEMS element. The drive mechanism 80 ″ drives the mirror to rotate or swing continuously or intermittently.

In the example illustrated in FIG. 3G, the drive mechanism 80″ swings the mirror (the input side optical system 50″) about the first axis AX1. The first axis AX1 may be parallel or non-parallel to the reflecting surface of the first reflecting layer 67. The mirror (the input side optical system 50 ″) swings around the first axis AX<b>1, so that the reflection spot 68 moves in a direction parallel to the direction indicated by the arrow E<b>1 in FIG. 3H.

In the example illustrated in FIG. 3G, the drive mechanism 80″ swings the mirror (input side optical system 50″) also about the second axis AX2. The second axis AX2 is an axis different from the first axis AX1. The second axis AX2 may be an axis perpendicular to the first axis AX1, or may be an axis perpendicular to the first axis AX1 and an axis parallel to the reflective surface of the first reflective layer 67. The mirror (the input side optical system 50 ″) swings around the second axis AX2, whereby the reflection spot 68 moves in a direction parallel to the direction indicated by the arrow E2 in FIG. 3G.

In the fourth modification shown in FIGS. 3G and 3H, the position of the reflection spot 68 of the coaxial light C on the first reflection layer 67 moves. As a result, the heat load acting on the first laser gain medium 62 is dispersed. In the fourth modification, the mirror (input side optical system 50″) swings or rotates about the first axis AX1 and swings or rotates about the second axis AX2. Therefore, the reflection spot 68 of the coaxial light C on the first reflection layer 67 moves two-dimensionally on the first reflection layer 67. As a result, the heat load acting on the first laser gain medium 62 is further dispersed. Further, in the fourth modified example, the input side optical system 50 ″ is configured by a mirror. Therefore, the axis shift between the seed light A and the excitation light B is suppressed as compared with the case where the oscillation of the parallel flat plate transmission plate is used.

In the fourth modification, the mirror (the input side optical system 50″) swings or rotates about the first axis AX1 and swings or rotates about the second axis AX2. However, the swinging or rotating of the mirror (input side optical system 50 ″) may be performed only around one axis. In the example shown in FIGS. 3I and 3J, the mirror swings or rotates about the first axis AX1, but does not swing or rotate about an axis different from the first axis AX1. In this case, when the mirror (input side optical system 50″) swings or rotates about the first axis AX1, the reflection spot 68 is one-dimensionally, that is, linearly on the first reflection layer 67. Moving. It should be noted that in the example shown in FIGS. 3I and 3J, the drive mechanism 80 ″ can be more simplified than in the examples shown in FIGS. 3G and 3H.

(Fifth Modification of First Embodiment)
3K to 3M are plan views schematically showing a laser amplification system 30E according to a fifth modified example of the first embodiment. In the laser amplification system 30E of the fifth modified example, components having the same functions as the components of the laser amplification system 30 of the first embodiment are given the same drawing numbers, and repeated explanations are omitted.

The example described in FIGS. 3K to 3M is different from the example described in FIG. 3A in that the cooling mechanism 70 is arranged in the amplifier 60. Other configurations in FIGS. 3K to 3M are similar to the configuration in FIG. 3A. The cooling mechanism 70 is a mechanism for cooling the amplifier 60 (in particular, the laser gain medium such as the first laser gain medium 62).

In the example described in FIG. 3K, the cooling mechanism 70 includes a heat sink. The heat sink is made of a material having a high thermal conductivity, for example, a metal material. In the example illustrated in FIG. 3K, the heat sink (cooling mechanism 70) is arranged on the back surface side of the first laser gain medium 62 (the side on which the first reflection layer 67 is provided). The heat sink is arranged in contact with the first reflective layer 67.

In the example shown in FIG. 3K, the cooling mechanism 70 further suppresses the temperature rise of the first laser gain medium 62. The cooling mechanism 70 may be applied to the amplifier 60 (more specifically, the back surface side of the first laser gain medium 62) in the example described in FIGS. 3C, 3D, 3G, and 3I. The cooling mechanism 70 may also be applied to the amplifier 60' in the example described in FIG. 3E. For example, the first heat sink (cooling mechanism 70) may be arranged in contact with the first reflective layer 67, and the second heat sink (cooling mechanism 70) may be arranged in contact with the second reflective layer 67-2. ..

In the example illustrated in FIG. 3L, the cooling mechanism 70 supplies a refrigerant flow path 72 and a refrigerant (for example, water, a liquid such as liquefied nitrogen, liquefied helium, or a gas such as air) to the refrigerant flow path 72. And a supply mechanism 74 (for example, a refrigerant tank, a refrigerant supply pump, etc.). At least a part of the coolant channel 72 may be arranged along the first reflective layer 67. At least a part of the coolant channel 72 may be arranged in parallel with the first reflective layer 67. Further, in the example shown in FIG. 3L, the coolant channel 72 is arranged on the back surface side of the first laser gain medium 62 (the side on which the first reflection layer 67 is provided).

In the example illustrated in FIG. 3L, the temperature of the first laser gain medium 62 is further suppressed by the coolant flowing through the coolant flow path 72. The coolant channel 72 may be applied to the amplifier 60 (more specifically, the back surface side of the first laser gain medium 62) in the examples described in FIGS. 3C, 3D, 3G, and 3I. Also, the refrigerant flow path 72 may be applied to the amplifier 60' in the example described in FIG. 3E. For example, at least a part of the coolant channel 72 may be arranged along the first reflective layer 67, and at least a part of the coolant channel 72 may be arranged along the second reflective layer 67-2. ..

The example described in FIG. 3M is a combination of the example described in FIG. 3K and the example described in FIG. 3L. The cooling mechanism 70 includes a heat sink, a refrigerant flow path 72, and a refrigerant supply mechanism 74 (for example, a liquid such as water, liquefied nitrogen, liquefied helium, or a gas such as air) supplied to the refrigerant flow path 72 (for example, water). , A refrigerant tank, a refrigerant supply pump, etc.). In the example shown in FIG. 3M, the coolant flow path 72 is provided inside the heat sink. Alternatively, the coolant channel 72 may supply coolant to the surface of the heat sink.

In the example described in FIG. 3M, the heat sink and the coolant flow path 72 further suppress the temperature rise of the first laser gain medium 62. The heat sink and the coolant channel 72 may be applied to the amplifier 60 (more specifically, the back surface side of the first laser gain medium 62) in the example illustrated in FIGS. 3C, 3D, 3G, and 3I. Good. Also, the heat sink and coolant flow path 72 may be applied to the amplifier 60' in the example described in Figure 3E. For example, the first heat sink and the coolant channel 72 are arranged on the back side of the first laser gain medium 62, and the second heat sink and the second coolant channel are arranged on the back side of the second laser gain medium 62-2. May be done.

(Second embodiment)
A laser amplification system 30A-1 according to the second embodiment will be described with reference to FIGS. 4A and 4B. FIG. 4A is a plan view schematically showing the laser amplification system 30A-1, and FIG. 4B is a side view schematically showing the laser amplification system 30A-1. In FIG. 4B, in order to avoid complication of the drawing, the components other than the input side optical system 50′″ and the amplifier 60 are not shown. Further, in the laser amplification system 30A-1 according to the second embodiment, components having the same functions as those of the components of the laser amplification system 30 according to the first embodiment are given the same drawing numbers, and repeated description will be given. Omit it.

The laser amplification system 30A-1 in the second embodiment is different from the input side optical system 50 in the laser amplification system 30 of the first embodiment in the configuration of the input side optical system 50'''.

The input side optical system 50 ″″ is an optical system arranged between the first optical element 40 and the amplifier 60. The input side optical system 50 ″″ receives the coaxial light C from the first optical element 40. The input side optical system 50 ′″ supplies the coaxial light C to the amplifier 60. The input side optical system 50 ″″ includes a first mirror 50-1 and a second mirror 50-2.

The first mirror 50-1 receives the coaxial light C from the first optical element 40. The first mirror 50-1 reflects the coaxial light C and supplies the coaxial light C to the second mirror 50-2. The second mirror 50-2 is arranged between the first mirror 50-1 and the amplifier 60. The coaxial light C from the first mirror 50-1 is incident on the second mirror 50-2, and the second mirror 50-2 reflects the coaxial light C. The coaxial light C reflected by the second mirror 50-2 is supplied to the amplifier 60.

The first mirror 50-1 is a polygon mirror in the example illustrated in FIG. 4A, but may be another mirror (galvano mirror, piezo mirror, MEMS mirror). The second mirror 50-2 is a polygon mirror in the example illustrated in FIG. 4A, but may be another mirror (galvano mirror, piezo mirror, MEMS mirror).

In the example illustrated in FIG. 4A, the rotation or swing of the first mirror 50-1 is performed by the first drive mechanism 80-1. The first drive mechanism 80-1 includes, for example, a motor and a power transmission mechanism. In the example illustrated in FIG. 4A, the first drive mechanism 80-1 is mechanically connected to the first mirror 50-1.

The first drive mechanism 80-1 is driven based on a command signal (for example, an electric signal) from the control device 90. In the example illustrated in FIG. 4A, the control device 90 and the first drive mechanism 80-1 are electrically connected to each other, and the first drive mechanism 80-1 is based on a command signal from the control device 90. 1 Drive the mirror 50-1. The first drive mechanism 80-1 rotates or swings the first mirror 50-1 around the axis X1 continuously or intermittently.

In the example illustrated in FIG. 4A, the rotation or swing of the second mirror 50-2 is performed by the second drive mechanism 80-2. The second drive mechanism 80-2 includes, for example, a motor and a power transmission mechanism. In the example illustrated in FIG. 4A, the second drive mechanism 80-2 is mechanically connected to the second mirror 50-2.

The second drive mechanism 80-2 is driven based on a command signal (for example, an electric signal) from the control device 90. In the example illustrated in FIG. 4A, the control device 90 and the second drive mechanism 80-2 are electrically connected to each other, and the second drive mechanism 80-2 is based on a command signal from the control device 90. 2 Drive the mirror 50-2. The second driving mechanism 80-2 rotates or swings the second mirror 50-2 around the axis X2 continuously or intermittently. The first drive mechanism 80-1 and the second drive mechanism 80-2 constitute a drive mechanism that drives the input side optical system 50 ″″.

(Parallel incidence mode)
The control device 90 sends a control signal to the drive mechanism (the first drive mechanism 80-1 and the second drive mechanism 80-2). In the example shown in FIGS. 4A and 4B, the controller 90 can execute the parallel incidence mode in which the incident position 65 on the amplifier 60 is changed while the incident direction D on the amplifier 60 is fixed. In the parallel incidence mode, the amplifier 60 outputs amplified lights M (see the optical paths M1 and M2 in FIG. 4B) that are parallel to each other. The incident angle with respect to the surface 63 in the incident direction D is, for example, larger than 0 degree and smaller than 90 degree.

An example of the parallel incidence mode will be described with reference to FIG. 4C. FIG. 4C shows the first mirror 50-1 and the second mirror 50-2. The first mirror 50-1 includes a first reflecting surface 52-1 and the second mirror 50-2 includes a second reflecting surface 52-2. The coaxial light C incident on the first mirror 50-1 is reflected by the first reflecting surface 52-1 of the first mirror 50-1 and the second reflecting surface 52-2 of the second mirror 50-2, The light is emitted along the optical path C1 or the optical path C2. In the example illustrated in the upper diagram of FIG. 4C, the first reflecting surface 52-1 and the second reflecting surface 52-2 are parallel to each other. For this reason, the coaxial light C incident on the first mirror 50-1 and the coaxial light emitted along the optical path C1 are parallel to each other.

In the lower diagram of FIG. 4C, the first mirror 50-1 rotates by the first angle θ in the R1 direction from the state shown in the upper diagram of FIG. 4C, and the second mirror 50-2 moves in the R2 direction (R1 direction). The state after the second angle θ (first angle=second angle) is rotated in the same direction). In the example illustrated in the lower side of FIG. 4C, the first reflecting surface 52-1 and the second reflecting surface 52-2 are parallel to each other. Therefore, the coaxial light C incident on the first mirror 50-1 and the coaxial light C emitted along the optical path C2 are parallel to each other. From the above, in FIG. 4C, it is understood that the optical path C1 and the optical path C2 are parallel to each other. That is, in the example illustrated in FIG. 4C, the control device 90 controls the drive mechanism (first drive mechanism 80-1) so that the first reflective surface 52-1 and the second reflective surface 52-2 are parallel to each other. And a control signal to the second drive mechanism 80-2). As a result, the parallel incidence mode is realized.

In the example illustrated in FIGS. 4A to 4C, the controller 90 determines that the magnitude of the swing speed or the rotation speed of the first mirror 50-1 is equal to the swing speed of the second mirror 50-2. You may control the 1st drive mechanism 80-1 and the 2nd drive mechanism 80-2 so that it may become equal to the magnitude|size or the magnitude|size of a rotation speed. Further, the control device 90 controls that the swing direction or the rotation direction of the first mirror 50-1 (the swing direction R1 or the rotation direction R1 around the axis X1) causes the second mirror 50-2 to swing. The first drive mechanism 80-1 and the second drive mechanism 80-2 may be controlled so that the first drive mechanism 80-1 and the second drive mechanism 80-2 are in the same direction as the rotation direction (the swinging direction R2 around the axis X2 or the rotation direction R2).

Note that the control in the parallel incidence mode is not limited to the example described in FIG. 4C. If the control in the parallel incidence mode is the control to change the incident position 65 to the amplifier 60 with the incident direction D to the amplifier 60 being fixed, how to control the first mirror 50-1 and the second mirror 50-2. It may be controlled to.

In the example shown in FIG. 4B, the parallel incident mode is executed, so that the reflected spot 68 moves continuously or intermittently from the position shown by reference numeral 68D1 to the position shown by reference numeral 68D2 (in FIG. 4B). (See arrow labeled E). With the movement of the position of the reflection spot 68, the optical path of the amplified light M moves from the optical path indicated by the reference symbol M1 to the optical path indicated by the reference symbol M2. The optical path M1 and the optical path M2 are parallel to each other.

The second embodiment has the same effects as the effects of the first embodiment. Further, in the second embodiment, it is possible to execute the parallel incidence mode in which the incident direction D to the amplifier 60 is made constant. In the parallel incidence mode, mutually amplified light is output. When amplified light that is parallel to each other is output, compared to when amplified light that is not parallel to each other is output, the amplified light is handled, for example, to the target of the amplified light (object to be processed or object to be destroyed). It becomes easy to control the guidance. Further, in the first embodiment, the width between the optical paths (the distance between the optical path C1 and the optical path C2 in FIG. 3B) increases in the amplifier as the coaxial light C advances. On the other hand, in the parallel incidence mode, the width between the optical paths (the distance between the optical path C1 and the optical path C2 in FIG. 4B) does not increase as the coaxial light C advances in the amplifier. Therefore, the laser gain medium can be downsized. In particular, when a plurality of amplification units are arranged along the traveling direction of the coaxial light, the effect of downsizing is remarkable. The effect will be described using the following first modified example.

(First Modification of Second Embodiment)
FIG. 4D is a plan view schematically showing the laser amplification system 30B-1 of the first modified example of the second embodiment. FIG. 4E is a side view schematically showing the laser amplification system 30B-1 of the first modified example of the second embodiment. The laser amplification system 30B-1 of the first modification has the same functions as the components of the laser amplification system of the second embodiment and the first embodiment (and each modification of the first embodiment). The same drawing number is given to the component, and the repeated description is omitted.

In the example described in FIGS. 4D and 4E, the amplifier 60 of FIGS. 4A and 4B is replaced by an amplifier 60'. Other configurations in FIGS. 4D and 4E are similar to those in FIGS. 4A and 4B.

The amplifier 60' includes a first-stage amplification unit 60-1 and a second-stage amplification unit 60-2. The first-stage amplification unit 60-1 includes a first laser gain medium 62 and a first reflection layer 67. The second-stage amplification unit 60-2 also includes a second laser gain medium 62-2 and a second reflective layer 67-2. The functions of the first laser gain medium 62 and the first reflection layer 67 shown in FIGS. 4D and 4E are the same as the functions of the first laser gain medium 62 and the first reflection layer 67 shown in FIGS. 3A and 3B, respectively. Is. The functions of the second laser gain medium 62-2 and the second reflection layer 67-2 shown in FIGS. 4D and 4E are the same as those of the second laser gain medium 62-2 and the second reflection layer 62-2 shown in FIGS. 3E and 3F. The functions of the layers 67-2 are the same. Therefore, repeated description of the first laser gain medium 62, the first reflection layer 67, the second laser gain medium 62-2, and the second reflection layer 67-2 will be omitted. Although the number of amplification units is two in the example illustrated in FIGS. 4D and 4E, the number of amplification units may be three or more.

As can be understood from FIGS. 4D and 4E, the incident position 65-2 of the coaxial light C on the second laser gain medium 62-2 is changed by driving the input side optical system 50. On the other hand, the incident direction D′ of the coaxial light C on the second laser gain medium 62-2 is constant.

By changing the incident position 65-2, the position of the reflection spot 68-2 on the second reflection layer 67-2 moves. In the example illustrated in FIG. 4E, the reflection spot 68-2 corresponding to the optical path C1 is the reflection spot 68D1-2, and the reflection spot 68-2 corresponding to the optical path C2 is the reflection spot 68D2-2.

In the example shown in FIG. 4E, the incident direction D of the coaxial light C on the first laser gain medium 62 is constant, and the incident direction D′ of the coaxial light C on the second laser gain medium 62-2 is constant. .. Therefore, in the amplifier 60', the width between the optical paths (the distance between the optical paths C1 and C2 in FIG. 4E) does not increase as the coaxial light C advances. Therefore, in the example shown in FIG. 4E, the size of the second laser gain medium 62-2 can be further reduced as compared with the example shown in FIG. 3F.

The first modified example of the second embodiment has the same effects as the second embodiment. In addition, in the first modification, the amplifier includes the first-stage amplification unit 60-1 and the second-stage amplification unit 60-2. Therefore, in the first modification, a laser amplification system having a higher amplification factor of seed light can be realized as compared with the examples described in FIGS. 4A and 4B. In addition, in the first modification of the second embodiment, the second laser gain medium 62-2 can be downsized.

(Second Modification of Second Embodiment)
FIG. 4F is a plan view schematically showing the laser amplification system 30C-1 of the second modified example of the second embodiment. In addition, in the laser amplification system 30C-1 of the second modified example, the same drawing number is given to the component having the same function as the component of the laser amplification system 30A-1 of the second embodiment, and the repeated description will be given. Is omitted.

The example shown in FIG. 4F is different from the example shown in FIG. 4A in that a cooling mechanism 70 is arranged in the amplifier 60. Other configurations in FIG. 4F are similar to those in FIG. 4A.

The cooling mechanism 70 may be the same as the cooling mechanism 70 illustrated in FIG. 3K, the cooling mechanism 70 illustrated in FIG. 3L, or the cooling mechanism 70 illustrated in FIG. 3M. It may be.

In the example shown in FIG. 4F, the cooling mechanism 70 suppresses the temperature rise of the first laser gain medium 62.

The cooling mechanism 70 may be applied to the first modified example of the second embodiment (specifically, the amplifier 60' in the example described in FIG. 4D).

(Third Embodiment)
A laser amplification system 30A-2 according to the third embodiment will be described with reference to FIGS. 5A and 5B. 5A is a plan view schematically showing the laser amplification system 30A-2, and FIG. 5B is a side view schematically showing the laser amplification system 30A-2. In FIG. 5B, in order to avoid complication of the drawing, the components other than the input side optical system 50′″, the amplifier 60, and the output side optical system 55 are omitted. Further, in the laser amplification system 30A-2 according to the third embodiment, the same function as the constituent elements of the laser amplification system 30 according to the first embodiment or the constituent elements of the laser amplification system 30A-1 according to the second embodiment. The same drawing number is given to the component having “”, and the repeated description is omitted.

The laser amplification system 30A-2 in the third embodiment is different from the laser amplification system 30A-1 in the second embodiment in that an output side optical system 55 is provided.

The output side optical system 55 receives the amplified light M from the amplifier 60. Further, the output side optical system 55 collects the amplified light M. Further, the output side optical system 55 emits the amplified light M in the fixed direction F. As will be described later, the output side optical system 55 emits the amplified light M in the fixed direction F regardless of the movement of the position of the reflection spot 68. The output side optical system 55 may emit the amplified light M from the fixed position P in the fixed direction F regardless of the movement of the position of the reflection spot 68.

In the example illustrated in FIGS. 5A and 5B, the output side optical system 55 includes a third mirror 55-3 and a fourth mirror 55-4. The output side optical system 55 may optionally include one or more optical elements 55-5 other than the third mirror and the fourth mirror.

The third mirror 55-3 receives the amplified light M from the amplifier 60. The third mirror 55-3 is arranged between the amplifier 60 and the fourth mirror 55-4. The third mirror 55-3 reflects the amplified light M and supplies the amplified light M to the fourth mirror 55-4. The amplified light M from the third mirror 55-3 is incident on the fourth mirror 55-4, and the fourth mirror 55-4 reflects the amplified light M. The amplified light M reflected by the fourth mirror 55-4 is output as output laser light to the outside of the laser amplification system 30A-2 via an output window (not shown in FIGS. 5A and 5B). It

The third mirror 55-3 is a polygon mirror in the example shown in FIG. 5A, but may be another mirror (galvano mirror, piezo mirror, MEMS mirror). The fourth mirror 55-4 is a polygon mirror in the example shown in FIG. 5A, but may be another mirror (galvano mirror, piezo mirror, MEMS mirror).

In the example illustrated in FIG. 5A, the rotation or swing of the third mirror 55-3 is performed by the third drive mechanism 85-3. The third drive mechanism 85-3 includes, for example, a motor and a power transmission mechanism. In the example illustrated in FIG. 5A, the third drive mechanism 85-3 is mechanically connected to the third mirror 55-3.

The third drive mechanism 85-3 is driven based on a command signal (for example, an electric signal) from the control device 90. In the example illustrated in FIG. 5A, the control device 90 and the third drive mechanism 85-3 are electrically connected, and the third drive mechanism 85-3 is based on a command signal from the control device 90. 3 The mirror 55-3 is driven. The third drive mechanism 85-3 rotates or swings the third mirror 55-3 around the axis X3 continuously or intermittently.

In the example shown in FIG. 5A, the rotation or swing of the fourth mirror 55-4 is performed by the fourth drive mechanism 85-4. The fourth drive mechanism 85-4 includes, for example, a motor and a power transmission mechanism. In the example shown in FIG. 5A, the fourth drive mechanism 85-4 is mechanically connected to the fourth mirror 55-4.

The fourth drive mechanism 85-4 is driven based on a command signal (for example, an electric signal) from the control device 90. In the example illustrated in FIG. 5A, the control device 90 and the fourth drive mechanism 85-4 are electrically connected to each other, and the fourth drive mechanism 85-4 operates based on a command signal from the control device 90. 4 The mirror 55-4 is driven. The fourth drive mechanism 85-4 rotates or swings the fourth mirror 55-4 around the axis X4 continuously or intermittently. The third drive mechanism 85-3 and the fourth drive mechanism 85-4 configure a drive mechanism that drives the output side optical system 55.

(Condensing mode)
The control device 90 sends a control signal to the drive mechanism (the third drive mechanism 85-3 and the fourth drive mechanism 85-4). In the example described in FIGS. 5A and 5B, the control device 90 can execute the light collection mode in which the amplified light M from the amplifier 60 is collected. In the light collecting mode, the control device 90, for example, causes the third reflecting surface 56-3 of the third mirror 55-3 and the fourth reflecting surface 56-4 of the fourth mirror 55-4 to be parallel to each other. , And controls the third drive mechanism 85-3 and the fourth drive mechanism 85-4.

More specifically, in the light collecting mode, the control device 90 determines that the magnitude of the swing speed or the rotation speed of the third mirror 55-3 is the magnitude of the swing speed of the fourth mirror 55-4. Alternatively, the third drive mechanism 85-3 and the fourth drive mechanism 85-4 are controlled so as to be equal to the magnitude of the rotation speed. Further, in the light collecting mode, the control device 90 causes the fourth mirror 55-4 to swing when the swinging direction or the rotating direction of the third mirror 55-3 (the swinging direction R3 around the axis X3 or the rotating direction R3). The third drive mechanism 85-3 and the fourth drive mechanism 85-4 are controlled so as to be in the same direction as the rotational direction (the swing direction R4 around the axis X4 or the rotational direction R4).

Further, in the light collecting mode, the control device 90 causes, for example, the swinging direction or the rotating direction of the third mirror 55-3 (the swinging direction R3 or the rotating direction R3 around the axis X3) of the second mirror 50-2. The second drive mechanism 80-2 and the third drive mechanism 85-3 are controlled so as to be in the same direction as the swing direction or the rotation direction (the swing direction R2 around the axis X2 or the rotation direction R2). Further, the control device 90 causes the magnitude of the swing speed or the rotation speed of the third mirror 55-3 to be equal to the magnitude of the swing speed or the rotation speed of the second mirror 50-2. Alternatively, the second drive mechanism 80-2 and the third drive mechanism 85-3 may be controlled.

In the light collecting mode, the amplified light M is emitted in the fixed direction F. When the amplified light M is emitted in the fixed direction F, compared with the case where the emission direction of the amplified light M is changed, the amplified light is handled, for example, the target of the amplified light (processing target or destruction). Guidance control to the object) becomes easy. The control by the control device 90 in the light collecting mode is not limited to the above example.

In the example illustrated in FIGS. 5A and 5B, the first mirror 50-1 that is an optical element that configures the input side optical system 50′″ and the fourth mirror 55-4 that configures the output side optical system 55 are , Are arranged symmetrically with respect to each other along the optical path of the seed light (or with respect to the amplifier 60). The first mirror 50-1 and the fourth mirror 55-4 may be composed of the same component. Costs can be reduced by using common parts. In the example shown in FIGS. 5A and 5B, the second mirror 50-2, which is an optical element forming the input side optical system 50′″, and the third mirror 55-3 forming the output side optical system 55. And are arranged symmetrically with respect to each other along the optical path of the seed light (or with respect to the amplifier 60). The second mirror 50-2 and the third mirror 55-3 may be composed of the same component. Costs can be reduced by using common parts. The first mirror 50-1 to the fourth mirror 55-4 may all be configured by the same component.

The laser amplification system may include the direction adjuster 59. The direction adjuster 59 receives the amplified light M from the output side optical system 55 (receives the amplified light M from the amplifier 60 when the output side optical system 55 does not exist), and sets it as a target TA (processing target, destruction target, etc.). The traveling direction of the amplified light is adjusted so that the amplified light M travels toward it. The direction adjuster 59 may include, for example, a mirror 59A and a drive mechanism 59B (motor or the like) that adjusts the angle of the mirror 59A. The configuration of the direction adjuster 59 may be applied to the above-described first embodiment or second embodiment.

(First Modification of Third Embodiment)
FIG. 5C is a plan view schematically showing a laser amplification system 30B-2 of the first modified example of the third embodiment. Further, FIG. 5D is a side view schematically showing the laser amplification system 30B-2 of the first modified example of the third embodiment. In the laser amplification system 30B-2 of the first modified example, the same drawing number is given to the component having the same function as the component of the laser amplification system 30B-1 of the third embodiment, and the repeated description will be given. Is omitted.

In the example shown in FIGS. 5C and 5D, the output side optical system 55 in FIGS. 5A and 5B is replaced with an output side optical system 55'. Other configurations in FIGS. 5C and 5D are similar to those in FIGS. 5A and 5B.

The output side optical system 55' is a fixed type condensing optical system. In the fixed type condensing optical system, the optical elements (for example, the convex lens 57 and the concave lens 58 described later) that configure the output side optical system 55' are not driven during the operation of the laser amplification system 30B-2. In other words, during the operation of the laser amplification system 30B-2, the optical elements (for example, the convex lens 57 and the concave lens 58 described later) forming the output side optical system 55' are not changed in position and their angles are not changed.

An example of the output side optical system 55' will be described with reference to FIGS. 5C and 5D. The output side optical system 55 ′ includes a convex lens 57 and a concave lens 58. The convex lens 57 collects the amplified light M. When the parallel incidence mode described above is executed, the amplified light M incident on the convex lens 57 is parallel light (in other words, the optical path C1 and the optical path C2 in FIG. 5D are parallel to each other). The concave lens 58 outputs the condensed amplified light M from the fixed position P in the fixed direction F.

The first modification of the third embodiment has the same effects as the third embodiment. In the example shown in FIGS. 5C and 5D, the output side optical system 55' is a fixed type condensing optical system. Therefore, in the example illustrated in FIGS. 5C and 5D, the drive mechanism can be simplified or omitted as compared with the examples illustrated in FIGS. 5A and 5B.

(Second Modification of Third Embodiment)
FIG. 5E is a plan view schematically showing the laser amplification system 30C-2 according to the second modified example of the third embodiment. Further, FIG. 5F is a side view schematically showing a laser amplification system 30C-2 according to a second modification of the third embodiment. In addition, in the laser amplification system 30C-2 of the second modified example, regarding the components having the same functions as the components of the laser amplification system of the third embodiment (and the first modified example of the second embodiment), The same drawing number is given and repeated explanation is omitted.

In the example described in FIGS. 5E and 5F, the amplifier 60 of FIGS. 5A and 5B is replaced by an amplifier 60″. Other configurations in FIGS. 5E and 5F are similar to those in FIGS. 5A and 5B.

The amplifier 60 ″ includes a first-stage amplification unit 60-1, a second-stage amplification unit 60-2, and a third-stage amplification unit 60-3. The first-stage amplification unit 60-1 includes a first laser gain medium 62 and a first reflection layer 67, and the second-stage amplification unit 60-2 includes a second laser gain medium 62-2 and a second laser gain medium 62-2. The second amplification layer 60-3 includes the second reflection layer 67-2, and the third-stage amplification unit 60-3 includes the third laser gain medium 62-3 and the third reflection layer 67-3. The materials of the third laser gain medium 62-3 and the third reflection layer 67-3 may be the same as the materials of the first laser gain medium 62 and the first reflection layer 67. Although the number of amplification units is three in the example shown in FIGS. 5E and 5F, the number of amplification units may be two, or may be four or more.

In the example illustrated in FIG. 5E, the incident direction D of the coaxial light C on the first laser gain medium 62 is constant, and the incident direction D′ of the coaxial light C on the second laser gain medium 62-2 is constant. The incident direction D″ of the coaxial light C on the third laser gain medium 62-3 is constant. Therefore, in the amplifier 60 ″, the width between the optical paths (the distance between the optical paths C<b>1 and C<b>2 in FIG. 5F) does not increase as the coaxial light C advances. Therefore, in the example shown in FIG. 5F, the size of the second laser gain medium 62-2 can be reduced as compared with the example shown in FIG. 3F. Further, in the example shown in FIG. 5F, the size of the third laser gain medium 62-3 can be reduced.

The second modification of the third embodiment has the same effects as the third embodiment. In addition, in the second modification, the amplifier includes a plurality of amplification units. Therefore, in the second modification, a laser amplification system having a higher amplification factor of seed light can be realized as compared with the examples described in FIGS. 5A and 5B. In addition, in the second modification of the third embodiment, the laser gain medium can be downsized.

(Third Modification of Third Embodiment)
FIG. 5G is a plan view schematically showing a laser amplification system 30D-2 according to a third modified example of the third embodiment. In the laser amplification system 30D-2 of the third modified example, the same drawing number is given to the component having the same function as the component of the laser amplification system 30A-2 of the third embodiment, and the repeated description will be given. Is omitted.

The example shown in FIG. 5G is different from the example shown in FIG. 5A in that the cooling mechanism 70 is arranged in the amplifier 60. Other configurations in FIG. 5G are similar to those in FIG. 5A.

The cooling mechanism 70 may be the same as the cooling mechanism 70 illustrated in FIG. 3K, the cooling mechanism 70 illustrated in FIG. 3L, or the cooling mechanism 70 illustrated in FIG. 3M. It may be.

In the example shown in FIG. 5G, the cooling mechanism 70 suppresses the temperature rise of the first laser gain medium 62.

The cooling mechanism 70 may be applied to the first modified example or the second modified example of the third embodiment.

(Fourth Embodiment)
A laser amplification system 30A-3 according to the fourth embodiment will be described with reference to FIGS. 6A and 6B. FIG. 6A is a plan view schematically showing a laser amplification system 30A-3 according to the fourth embodiment. FIG. 6B is a sectional view schematically showing a laser amplification system 30A-3 according to the fourth embodiment.

The laser amplification system 30A-3 of the fourth embodiment has the same components as those of the laser amplification system 30A-2 of the third embodiment (or each modification of the laser amplification system of the third embodiment). The same figure number is given to the component having the function, and the repeated description is omitted.

The laser amplification system 30A-3 of the fourth embodiment includes a housing 100 surrounding the amplifier 60, and an output window 110 for outputting the amplified light M from the inside of the housing to the outside of the housing. In the housing 100, in addition to the amplifier 60, at least one of the seed light source 98, the excitation light source 99, the first optical element 40, the input side optical system 50, the output side optical system 55, and the coolant supply mechanism 74 is arranged. May be.

The laser amplification system 30A-3 includes a coolant channel 72 and a coolant supply mechanism 74 that supplies a coolant to the coolant channel 72. The refrigerant flowing through the refrigerant passage 72 cools the amplifier 60 (for example, the first laser gain medium 62). The coolant channel 72 includes discharge ports 101A and 101B that supply the coolant toward the output window 110. The outlet 101A is arranged inside the housing 100, and the outlet 101A supplies the refrigerant toward the inner surface of the output window 110 (the surface on the inner side of the housing). As a result, the inner surface of the output window 110 is cleaned. The outlet 101B is arranged outside the housing 100, and the outlet 101B supplies the refrigerant toward the outer surface of the output window 110 (the surface on the outside of the housing). As a result, the outer surface of the output window 110 is cleaned. The discharge port 101B and the portion of the refrigerant flow path 72 inside the housing are connected via an on-off valve 103. The refrigerant can be supplied to the discharge port 101B only when the opening/closing valve 103 is open. Note that dust, dirt, and the like are more likely to be accumulated outside the housing 100 than inside the housing 100. Therefore, it is meaningful to provide a mechanism for cleaning the outer surface of the output window 110.

The refrigerant flow path 72 includes refrigerant recovery mechanisms 102A and 102B. The recovery mechanism 102A recovers the refrigerant supplied from the outlet 101A toward the output window 110, and the recovered refrigerant is returned to the refrigerant supply mechanism 74. The recovery mechanism 102B recovers the refrigerant supplied from the outlet 101B toward the output window 110, and the recovered refrigerant is returned to the refrigerant supply mechanism 74. The recovery mechanism 102B and the portion of the refrigerant flow path 72 inside the housing are connected via an on-off valve 104.

In the fourth embodiment, a cooling medium used for cooling the amplifier is used to clean the optical element such as the output window. As a result, dust and dirt on the optical path are removed. By removing dust and dirt on the optical path, burn-in of the optical element (output window or the like) is prevented. Further, it is possible to prevent the transmission efficiency of the optical element (output window or the like) from being lowered, and to prevent the reflection efficiency of the optical element (mirror or the like) from being lowered.

In the example illustrated in FIGS. 6A and 6B, the cleaning mechanism for the output window 110 (for example, the emission ports 101A, 101B, etc.) has been described, but the cleaning mechanism may be included in the laser amplification system 30-4. It may be used for cleaning optical elements. In this case, a refrigerant discharge port is provided corresponding to each optical element to be cleaned, and a refrigerant recovery mechanism is provided corresponding to each optical element to be cleaned.

The configuration of the optical element cleaning mechanism or the housing in the fourth embodiment is also applied to the first embodiment, the second embodiment, the third embodiment, or each modified example of each embodiment. It is possible.

The present invention is not limited to the above-described embodiments, and it is apparent that each embodiment can be appropriately modified or changed within the scope of the technical idea of the present invention. Further, the various techniques used in each embodiment or modification can be applied to other embodiments or modifications as long as no technical contradiction occurs. The present invention does not exclude the techniques described in Patent Documents 1 to 5 described above. If the techniques described in Patent Documents 1 to 5 are combined with the present invention, the techniques described in Patent Documents 1 to 5 can be improved.

1 :laser amplifier 2 :laser gain medium 3 :reflecting film 4 :seed light 5 :excitation light 6 :reflection spot 10 :laser resonator 11 :cavity mirror 12 :cavity mirror 13 :laser gain medium 14 :parallel plate transmission Plate 15: Nonlinear optical crystal 16: Optical path 17: Optical path 18: Lamp 30: Laser amplification system 40, 40': First optical element 50, 50', 50", 50"': Input side optical system 50-1 : First mirror 50-2: Second mirror 51: Corner portion 52-1: First reflection surface 52-2: Second reflection surfaces 55, 55': Output side optical system 55-3: Third mirror 55-4 : Fourth mirror 55-5: optical element 56-3: third reflecting surface 56-4: fourth reflecting surface 57: convex lens 58: concave lens 59: direction adjuster 59A: mirror 59B: driving mechanism 60, 60', 60 '': Amplifier 60-1, 60-2, 60-3: Amplifying unit 62: First laser gain medium 62-2: Second laser gain medium 62-3: Third laser gain medium 63: Surface 64: Surface 65 , 65-2: incident position 67: first reflection layer 67-2: second reflection layer 67-3: third reflection layers 68, 68-2: reflection spot 70: cooling mechanism 72: refrigerant flow path 74: refrigerant supply Mechanisms 80, 80', 80'': Drive mechanism 80-1: First drive mechanism 80-2: Second drive mechanism 81: Motor 82: Output shaft 85-3: Third drive mechanism 85-4: Fourth drive Mechanism 90: Control device 98: Seed light source 99: Excitation light source 100: Enclosures 101A and 101B: Outlet ports 102A and 102B: Recovery mechanism 103: Open/close valve 104: Open/close valve 110: Output window A: Seed light B: Excitation light C : Coaxial light C1: Optical path C2: Optical paths D, D', D'': Incident direction M: Amplified light M1: Optical path M2: Optical path P: Fixed position

Claims (14)

A first optical element that receives the seed light and the excitation light and outputs the seed light and the excitation light as coaxial light;
An amplifier that receives the coaxial light, amplifies the seed light using the excitation light, and outputs amplified light obtained by amplifying the seed light,
An input side optical system which is arranged between the first optical element and the amplifier, receives the coaxial light from the first optical element, and supplies the coaxial light to the amplifier;
A drive mechanism for driving the input side optical system to change the incident direction of the coaxial light to the amplifier;
A control device for controlling the drive mechanism,
The amplifier is
A first laser gain medium into which the coaxial light is introduced and which amplifies the seed light;
A first reflection layer disposed on the back side of the surface of the first laser gain medium into which the coaxial light is introduced, and reflecting the coaxial light introduced into the first laser gain medium ;
A second laser gain medium for introducing the coaxial light from the first laser gain medium and amplifying the coaxial light;
A second reflection layer disposed on the back side of the surface of the second laser gain medium into which the coaxial light is introduced, the second reflection layer reflecting the coaxial light introduced into the second laser gain medium ,
A laser amplification system in which the control device controls the drive mechanism to change the incident direction to move the position of the reflection spot of the coaxial light on the first reflection layer. The laser amplification system according to claim 1, wherein
A laser amplification system in which the first laser gain medium is arranged away from the second laser gain medium. The laser amplification system according to claim 1 or 2, wherein
The input side optical system includes a first mirror that reflects the coaxial light,
The laser drive system, wherein the drive mechanism includes a first drive mechanism that swings or rotates the first mirror. The laser amplification system according to claim 3, wherein
The control device controls the first drive mechanism such that the first mirror swings or rotates about a first axis,
A laser amplification system in which the reflection spot moves on the first reflection layer by swinging or rotating the first mirror around the first axis. The laser amplification system according to claim 4, wherein:
The control device controls the first drive mechanism such that the first mirror swings or rotates about a second axis different from the first axis,
As the first mirror swings or rotates about the first axis and swings or rotates about the second axis, the reflection spot moves two-dimensionally on the first reflection layer. Laser amplification system. A laser amplification system according to any one of claims 1 to 5, wherein
Further comprising an output side optical system for receiving the amplified light, condensing the amplified light, and outputting the amplified light in a fixed direction,
The output side optical system is a laser amplification system that outputs the amplified light in the fixed direction regardless of the movement of the position of the reflection spot. The laser amplification system according to claim 6, wherein
The output side optical system is a fixed type condensing optical system. A laser amplification system. The laser amplification system according to claim 6, wherein
An input side optical element forming the input side optical system and an output side optical element forming the output side optical system are arranged symmetrically to each other. The laser amplification system according to claim 6, wherein
A third mirror which receives the amplified light from the amplifier and reflects the amplified light;
A fourth mirror which receives the amplified light from the third mirror and reflects the amplified light;
A third drive mechanism that swings or rotates the third mirror;
A fourth drive mechanism for swinging or rotating the fourth mirror,
A laser amplification system in which the third mirror and the fourth mirror constitute the output side optical system. The laser amplification system according to any one of claims 1 to 9,
A laser amplification system further comprising a cooling mechanism for cooling the first laser gain medium. The laser amplification system according to claim 10, wherein:
The laser amplification system, wherein the cooling mechanism includes a heat sink disposed in contact with the first reflective layer. The laser amplification system according to claim 10 or 11, wherein
The cooling mechanism is
A coolant flow path,
A laser amplification system, comprising: a coolant supply mechanism that supplies a coolant to the coolant flow path. The laser amplification system according to claim 12, wherein:
The cooling medium flow path includes a cooling medium outlet for supplying the cooling medium to an optical component,
A laser amplification system for cleaning the optical component with the coolant. The laser amplification system according to claim 13, wherein:
A housing surrounding the amplifier,
An output window for outputting the amplified light from the inside of the housing to the outside of the housing,
The optical component being cleaned is the output window. Laser amplification system.

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