JPS58178579A - laser oscillator - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a laser oscillator. In recent years, a stable laser oscillator with high output characteristics and little output fluctuation has been desired as a laser oscillator. .

An example of a resonator J) of a conventional gas flow laser oscillator is shown in FIG.

In the figure, 1 is a laser a, 2 is a total reflection mirror, 3 is an output coupling mirror, and constitutes an optical resonator L7. 3 and 4 are outside and θ of the gas introduction part, and 40 is an inner tube, which is -2 Numerals 7 and 6 constituting the heavy pipe are gaps between the end face of the inner pipe 4o and the end face of the laser #1, and 6o is a space for improving gas inflow. ,6
is an electrode, which is cylindrical or rod-shaped (pin-shaped). Reference numeral 7 indicates an electrode facing in the χ1 direction, and reference numerals 3, 8, and 9 indicate the flow direction of the medium dregs. 10 is the laser output. 7 In this example, the medium gas flows from both ends of the resonator in the direction of the arrow 8, flows along the inner tube 4o, is introduced into the laser tube 1 through the gap 6, and flows from the center of the resonator in the direction of the arrow 9. ejected in the direction. The centering is performed between electrodes 6 and 7.

FIG. 2 is an enlarged perspective view of the gas introduction portion in this configuration example, and FIG. 3 is an enlarged cross-sectional view.

In the conventional system shown in FIGS. 2 and 3, since the gap 5 is formed by the end face of the inner tube 40 and the laser tube 1, which is a cylinder of m length, the laser tube 1 is Since the gas uniformly flows into the laser tube 1, the gas flow is concentrated in the center of the laser tube 1, making it impossible to obtain a uniform flow velocity distribution. For this reason, the discharge point concentrates on one point, and the temperature of the electrode 6 often becomes high, and the discharge volume is small, making it impossible to obtain sufficient output3.Also, because this discharge point moves around irregularly, The output fluctuates every time, and sometimes the discharge stops. For this reason, it is not possible to increase the gas pressure or the input power, and the device has the disadvantage that it must be operated at a low output value in order to obtain stable output.

An object of the present invention is to eliminate the above-mentioned drawbacks and provide a laser oscillator with high output and high output stability.

FIG. 4 shows a structure of a resonator of a laser beam oscillator in an embodiment of the present invention. In this embodiment, the gas is introduced from both ends of the resonator, but the present invention is not limited to this. It should be noted that this method is applicable regardless of the method of introduction and the direction of gas flow.

In Fig. 4, the same number as C1 is given to the conventional chestnut and turning parts in Fig. 1, and detailed explanations are omitted. +f
A plurality of coupling passages 66 are provided on the laser tube 1 side of the inner ′θ401, and the medium gas is introduced into the laser [f1] through the coupling passages 66.

FIG. 6 is an enlarged perspective view of the waste introducing portion of the chestnut of this embodiment, and an enlarged sectional view 51 is shown in FIG. 6.

As shown in FIGS. 5 and 6, in this embodiment, a double structure is formed by the outer tube 401 and the inner tube 401, which also serves as an electrode, and a total reflection mirror 2 is provided at one end of the inner tube 401υ, which also serves as an electrode. and
A plurality of coupling passages 55 are provided at the other end of the inner tube 401 that also serves as an electrode. At this time, copper, titanium, etc. are preferable as the material for #4o1 among the electric wires.

The medium gas introduced between the outer tube 4 and the inner tube 401 that also serves as a polarizer is supplied to the laser beam from a plurality of coupling passages 65 provided in a part of the inner tube 401 that also serves as a city pole. Because it is forcibly ejected into f1, a turbulent flow is formed on the laser tube 1 side due to the force difference between the coupling passage 56 part and the part without coupling passage 55 and the collision of the ejected gases.JL, V-The tube The flow velocity distribution of the medium gas in the tube axis direction within the tube becomes uniform. This turbulence prevents the concentration of the discharge point 1514 and tends to increase the output because the discharge volume is uniformly expanded within the laser tube through which the laser beam passes. Due to this turbulent flow effect and the cooling effect of the gas and electrodes due to adiabatic expansion based on the introduction of gas from the narrow coupling passage 55 into the large diameter laser tube 1, it becomes possible to input more power, which increases the discharge speed. Since the output fluctuations caused by instability can be greatly reduced rlj, stable fluctuations can be obtained.

7 is an enlarged perspective view of a second embodiment of the gas introduction portion of the laser oscillator of the present invention. The same parts as in FIG. 3 and FIG. 3 is an example in which the inner tube 401 serving as an electrode is provided at a position slightly away from the end surface on the side of the laser tube 1. In this case as well, exactly the same effect as in the first embodiment can be obtained.

The coupling passage 55 may be installed near the end face of the inner tube 401 which also serves as an electrode.

Furthermore, although the shape of the coupling passage 66 is slit-like in both embodiments, it is not necessarily limited to this shape, and a slit-like shape is preferable.

In addition, in one embodiment, the case where the inner pipe 401 that also serves as an electrode is entirely made of the material 1 is described as an example; however, if the electrode material portion exists at least in the vicinity of the coupling passage 56, it will be sufficient to fulfill its role. can be fulfilled.

FIG. 8 shows a comparison of the output characteristics of the laser beam oscillator of the first embodiment shown in FIG. 5 and a conventional oscillator.
In the conventional method, as shown by the broken line, as the gas IV in the tube rises, the output fluctuation (particularly the large spike-like output change d that occurs when the Ink nt at the discharge point changes) increases.
Eventually, the discharge runs out and no more output can be extracted, but with this method, as shown by the solid line, it is possible to obtain a large output while keeping output fluctuations low.

As described in F below, the present invention provides a gas 70-1 type oscillator in which the gas introduction part into the laser tube has a dual tube structure, and a plurality of gas coupling passages are provided on the laser tube side of the inner tube that also serves as polarization. , this narrow combination JI! By ejecting the medium gas from the l path, the flow velocity of the medium gas in the radial direction within the laser tube is made uniform, and the concentration of discharge in the blue center is stopped by 1 (11), and high output is obtained. It is possible to stabilize discharge and reduce output fluctuations.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view showing the structure of the resonator section of a conventional Kas70-1 laser oscillator, Figure 2 is an enlarged perspective view of the gas introduction part in Figure 1, and Figure 3 is the gas introduction part in Figure 1. 4 is a sectional view showing the structure of the resonator section of a laser oscillator according to an embodiment of the present invention. FIG. 5 is an enlarged perspective view of the gas introduction part of the oscillator. Expansion of the introduction part ~
Fig. 7 is an enlarged perspective view of the υ implementation chest in addition to the gas introduction part of the laser oscillation of the present invention, and Fig. 8 is a diagram showing a comparison of the laser output characteristics of the present study and the conventional chest. 1゜1-
... Laser tube, 2 ... Total reflection mirror, 3 ...
Output coupling mirror, 4...outer tube of gas introduction section, 40...
Inner pipe of waste introduction part, 6-... Gap made by cylindrical end surface, 60...- Vacant chamber, 6, 7... City pole, 8, 9-...
Gas flow direction, 55...-coupling passage, 401. 4
i, polar dual use, cat. Name of agent Patent attorney J: Toshio Nakao and 1 other person Figure 1 Figure 3 Figure 4 Figure 5 667 Figure 6 Figure 7 Figure 8 is Nu Pressure

Claims (1)

[Scope of Claims] 1. The medium gas introduction part of the laser tube has a double tube structure having an outer tube and an inner tube, and a plurality of coupling passages are provided near the end surface of the inner tube on the laser tube side, and the A medium gas is introduced into the laser tube from a region surrounded by the outer tube and the inner tube through the coupling passage, and at least the vicinity of the coupling passage of the inner tube is made of an electrode material so that it also serves as an electrode. A laser oscillator featuring: 2. The laser oscillator according to claim 1, wherein the coupling path is slit-shaped.