JP3473540B2 - Semiconductor laser cooling device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor laser cooling apparatus, and more particularly to a semiconductor having a function of cooling a plurality of pumping light sources arranged in parallel around a laser medium and controlling an oscillation wavelength of each pumping light source. The present invention relates to a laser cooling device.

[0002]

2. Description of the Related Art In recent years, a semiconductor laser (Laser Dio) which has a high absorption efficiency of excitation and can obtain a high output from a small crystal volume.
de, hereinafter simply referred to as LD),
The pumping light source of the solid-state laser is changing from lamp pumping to LD pumping, and it is desired to further increase the LD output in the use for machining such as cutting and welding of metal materials.

By the way, as the output of the LD is increased, a cooling mechanism for cooling the LD is required.

For example, when a plurality of LDs are densely mounted as an excitation light source for high output, a huge amount of heat is generated, and therefore a cooling mechanism for reducing the absolute temperature and extending the life of the LDs is necessary. become.

Further, a cooling mechanism is required to prevent the deterioration of the laser oscillation efficiency by controlling the temperature of the LD so that the absorption spectrum between the laser oscillation wavelength of the LD and the excited laser medium such as YAG crystal does not occur. Is coming.

Particularly, since about 60% of the LD power becomes heat, for example, when a plurality of LDs are mounted at high density, the amount of heat exceeds several hundred watts, which is a cooling means such as normal forced air cooling. There may be a lack of capacity.

Conventionally, as this type of cooling mechanism, for example, a water cooling mechanism for cooling a supercomputer is known.

In this method, a pipe of cooling water is bent, and the pipe is installed on the surface of or inside a substrate to cool a semiconductor device mounted on the surface of the substrate.

When such a water cooling mechanism is applied to a semiconductor laser cooling device, an LD serving as an excitation light source is packaged with a heat transfer member such as copper having a high thermal conductivity, and cooling water is placed inside these heat transfer members. A method of cooling by flowing is conceivable.

For example, as a conventional example for cooling an LD and controlling the temperature, there is a "laser diode pumped solid-state laser device" disclosed in Japanese Patent Laid-Open No. 10-294513.

In this device, for example, as shown in FIG. 7, a plurality of high-power semiconductor laser modules each having four LDs 101a to 101d mounted around a YAG crystal 100 serving as a laser medium are arranged. . Note that only one module is shown here.

Further, the mounted LDs 101a to 101
d is in contact with and fixed to the radiators 102a to 102d, respectively. And these radiators 102a-102d
Are individually connected to the cooler 104 via the cooling paths 103a to 103d.

This cooler 104 includes radiators 102a-1a.
The LDs 101a to 101d are cooled by supplying cooling water to the cooling paths 103a to 103d of 02d.

The conventional semiconductor laser module having such a structure has the following features.

First, of the LDs 101a to 101d, the LD which emits the light having the longest oscillation wavelength, for example, the LD 10
The temperature is detected by the temperature sensor 107 provided in 1a,
Further, the LDs 101a to 1d are arranged so that the wavelengths of the light from the respective LDs 101a to 101d match the absorption spectrum of the laser medium.
01d connected to and fixed to each of the radiators 102a to 102a
The flow rate of the cooling water flowing through the cooling passages 103a to 103d of d is adjusted by the valves 105a to 105d. That is, the radiator 1
LD10 by adjusting the cooling capacity of 02a-102d itself
The temperature control is from 1a to 101d.

Next, the radiators 102a to 102d and the LD 1
01a to 101d and heat transfer members 106a to 106 such as beryllia or aluminum nitride having different thermal conductivities.
d is provided to control the temperature of the LDs 101a to 101d.
This is for the radiators 102a to 102d and the LDs 101a to 10d.
LD101a-10 by adjusting the thermal conductivity between 1d
1d temperature control.

Further, the radiators 102a to 102d and the LD1
01a to 101d and heat transfer member groups 106a to 106d
On the other hand, radiators 102a to 102d or LD 101a
The heat flux is changed by adjusting the contact area between the LDs 101a to 101d to control the temperature of the LDs 101a to 101d. As a method for actually adjusting the contact area, grooves are formed on the surfaces of the heat transfer member groups 106a to 106d, holes are formed, or the heat transfer member group 1 is used.
There is also a method of changing the shape of 06a to 106d itself. This is also in a broad sense, the radiators 102a to 102d.
And temperature control of the LDs 101a to 101d by adjusting the thermal conductivity between the LDs 101a to 101d.

Finally, the lengths and cross-sectional areas of the cooling passages 103a to 103d provided inside the radiators 102a to 102d are changed, or the routes of the cooling passages 103a to 103d running inside the radiators 102a to 102d are adjusted. By doing so, the oscillation wavelength and temperature of the mounted LDs 101a to 1101d are controlled. In a broad sense, this is also the temperature control of the LDs 101a to 101d by adjusting the cooling capacity of the radiators 102a to 102d themselves.

As described above, in the prior art, complicated temperature control was performed by making full use of various methods, and it was L
This is because the D manufacturing technology is immature and the oscillation wavelengths of the LDs vary, and individual optimal temperature control is required for each LD in order to compensate for this.

[0020]

On the other hand, the recent progress in the LD manufacturing technology is remarkable, and the variation in the oscillation wavelength of the LD due to the manufacturing problem, which has been a problem in the past, has been greatly reduced, and the high output of the LD is exclusively used. There is a demand for a powerful cooling device to cope with the above-mentioned trend.

That is, as described above, the temperature control method and the cooling device for individually controlling the temperature of each LD are effective methods from the viewpoint of controlling the oscillation wavelength, but under the recent situation in which the LD quality is stable, However, these methods and devices are over-engineering, and rather have the problem of hindering miniaturization and increasing costs.

[0022]

Therefore, one of the objects of the present invention is to realize a high power semiconductor laser capable of obtaining high power and high quality pumping light. It is an object of the present invention to provide a semiconductor laser cooling device that can be mounted at a high density and can remove a huge amount of heat generated at this time.

In addition, the oscillation wavelengths of a plurality of pumping light sources are made uniform to efficiently pump the laser medium to output a stable laser with high output, and a simple structure is possible without significantly improving the cooling device. Increasing the heat dissipation performance to obtain the cost reduction effect is part of the purpose.

[0024]

SUMMARY OF THE INVENTION The present invention is a semiconductor laser cooling device for cooling a plurality of pumping light sources arranged in parallel around a laser medium. In order to achieve the above-mentioned object, in particular, each pumping light source is provided. In order to dissipate heat by providing multiple radiator components that are made of metal with high thermal conductivity
Cooling paths along the alignment direction of the pump source on each of the body components
And the cooling path of each radiator component.
A peripheral groove is formed in at least one opening so that the elastic member
A ring-shaped body is fitted inside, and a plurality of radiator components are used as excitation light sources.
The block-shaped heat radiator is constructed by superposing and fixing along the alignment direction of the above, and at the same time, each of the annular bodies is exposed on both sides.
The annular body is compressed and elastically deformed by the heat body component.
By blocking the inner diameter, block the protrusions with a predetermined separation distance.
The heat radiator is formed in the cooling passage inside, and the opening portions at both ends of the cooling passage of the block-shaped heat radiator are connected to a cooling water supply cooler.

According to this structure, the heat radiated from the excitation light source is transmitted to the block-shaped heat radiator made of metal having high conductivity, and the cooling water flowing through the cooling passage formed in the block-shaped heat radiator is used. The block-shaped radiator is cooled. At this time, since the cooling water flowing through the cooling passage is agitated by the protrusions provided inside the cooling passage to form a turbulent flow, heat is evenly transferred from the wall surface of the cooling passage to the cooling water inside. Therefore, the cooling performance of the block-shaped radiator using the cooling water is improved. In addition, since the cooler itself that supplies the cooling water can be diverted from the conventional one,
No special capital investment is required for peripheral devices. As a result, it is possible to remove the enormous heat generated when a plurality of LDs serving as pumping light sources are mounted around the laser medium with high density, and obtain pumping light of high power and high quality. A high output semiconductor laser is realized. Further, since the cooling capacity of the cooling device is strong and the fluctuation of the oscillation wavelength in the LD is small with the recent improvement in manufacturing technology, the oscillation wavelengths of a plurality of pumping light sources are made uniform, and the efficiency of the laser medium is improved. Good pumping becomes possible, and a high-power and stable laser can be obtained. Specifically, a plurality of radiator components that are divided and formed corresponding to each excitation light source are provided, a cooling path is formed in each of the radiator components, and cooling in each radiator component is performed. A ring-shaped body made of an elastic member is fitted into the groove formed in at least one opening of the passage, and the plurality of heat-radiating body constituent elements are polymerized and fixed along the alignment direction of the excitation light source, and the ring-shaped body is formed. and so as to form a projection of each of the predetermined distance by a respective body is compressed by the heat radiating body component on both sides by elastic deformation reducing the diameter of the inner diameter of the annular body. this
Therefore, a simple manufacturing process such as polymerization connect inner fitting and the heat radiating body components parallel annular body made of machining and the elastic member in the circumferential grooves in the heat radiating body component, the block-shaped heat dissipating body having a projection into the cooling passage Can be formed. At this time, as the annular body made of an elastic member, for example, a commercially available material such as an o-ring for liquid leakage prevention can be used. When the O-ring is used, the O-ring itself forming the projection also serves as the liquid leakage preventing means of the block-shaped radiator, so that it is not necessary to provide a special liquid leakage preventing means as a separate component. Further, the inner diameter of the annular body, that is, the protrusion amount of the protrusion can be adjusted by changing the depth of the circumferential groove or the pressure contact force by the heat radiating body constituent elements on both sides to adjust the compression amount of the annular body. is there. For this reason, it becomes possible to easily form the protrusions corresponding to the required stirring function and perform the temperature control for adjusting the oscillation wavelength and the appropriate temperature control for cooling. It is also possible to adjust the inner diameter of the annular body, that is, the flow resistance of the cooling liquid, depending on the pumping capacity of the cooler. Moreover, since one block-shaped radiator is constructed by superposing a plurality of radiator components that are divided and formed corresponding to each excitation light source, it is easy to change the number of combinations of radiator components. The work makes it possible to arrange the pumping light source according to the size of the laser medium and the like. In this case, what is connected to the cooling water supply cooler is the opening of the two radiator components located at the outermost position of the plurality of radiator components that are superposed and connected.

[0026]

[0027]

Further, as a structure for forming the projections at a predetermined distance, a plurality of heat dissipating body constituent elements divided and formed corresponding to each excitation light source are provided, and each of the heat dissipating body constituent elements is provided with the above-mentioned structure. A structure in which a cooling passage is formed, one opening of the cooling passage in each radiator component is reduced in diameter, and a plurality of radiator components are polymerized and fixed along the alignment direction of the excitation light source is applied. You can also

In this case, the plurality of protrusions in the cooling passage of the radiator are constituted by the reduced diameter portion provided in one opening of the cooling passage of each radiator constituting element. Since this reduced diameter portion only needs to be provided in one opening of the radiator component, the machining process is simplified compared to the case where the reduced diameter portion is provided in the central portion or both sides of the cooling passage of each radiator component. Can be converted.

Here, as a means for providing a reduced diameter portion in one opening in the cooling passage of each radiator component, a peripheral groove is formed in the one opening, and the diameter is smaller than the inner diameter of the cooling passage. It is possible to apply a structure in which an annular member having a small inner diameter is fitted in the circumferential groove.

In this case, since the annular member forming the reduced diameter portion can be processed independently of the radiator component, there is an advantage that the whole processing operation is facilitated.

Further, as a means for providing a reduced diameter portion at one opening portion in the cooling passage of each radiator component,
It is also possible to use blind hole processing having a diameter corresponding to the inner diameter of the cooling passage and through hole processing having a smaller diameter than the blind hole processing.

In this case, the processing is performed only on the inside of the heat dissipating component which is the object of the removal processing, so that there is an advantage that the material for manufacturing the heat dissipating component is saved.

Further, the reduced diameter portion of the one opening may be formed with a taper surface which expands from the central portion in the axial direction of the reduced diameter portion toward both sides.

According to this construction, the action of the tapered surface prevents abrupt reduction and expansion of the flow passage in the cooling passage, so that the pressure rise of the cooling water is reduced and the load of the pump in the cooler is reduced. There is an advantage that

Further, instead of the taper surface that expands from the central portion in the axial direction of the reduced diameter portion toward both sides, a taper surface that expands from one end to the other end in the axial direction of the reduced diameter portion is adopted. It is also possible to do so.

In this case, it is possible to prevent either the rapid reduction or expansion of the flow passage in the cooling passage, and from the viewpoint of processing, the diameter is increased from the central portion toward both sides. There is an advantage that it is easier than when a tapered surface is provided.

Further, it is possible to form a plurality of cutouts axially penetrating the reduced diameter portion provided in one opening of the radiator component at a predetermined circumferential pitch. is there.

By providing the cutout portion, the stirring ability of the cooling water is significantly improved, and the heat transfer is promoted by the fluid vortices of various sizes generated by the stirring, so that a more efficient cooling function is achieved.

Also, an O-ring may be provided between a plurality of heat dissipating element constituents to serve as a liquid leakage preventing means.

In this structure, in particular, an annular member is fitted in the circumferential groove to reduce the diameter of one opening in the cooling path of the heat dissipating element, or blind hole processing and small-diameter through hole processing. It is effective for a structure in which one of the openings is reduced in diameter in combination.

[0042]

[0043]

[0044]

DETAILED DESCRIPTION OF THE INVENTION Some embodiments of the present invention will be described in detail below with reference to the drawings. Figure 1 (a)
Of the embodiments that can be envisioned by the present invention, a plan view showing a simplified appearance common to the embodiments in which a plurality of radiator components are polymerized and fixed to form one block radiator, and FIG. 1B is a simplified perspective view showing only the block-shaped radiator in the plan view of FIG. 1A.

The semiconductor laser cooling device 1 is shown in FIG.
As shown in FIG.
And a cooler 3. Of these, cooler 3
The configuration relating to the part is similar to that of the conventional cooler. That is, the cooler 3 has a function of cooling the cooling water to a predetermined temperature while sending, collecting and circulating the cooling water.

In the example shown in FIGS. 1A and 1B, an example is shown in which one heat radiator 2 is formed by polymerizing and fixing six heat radiator components 2a to 2f. The number can be arbitrarily adjusted according to the size of the YAG crystal 100 serving as the laser medium, and the number is not limited.

Each of the radiator components 2a to 2f is made of a metal having a high thermal conductivity, such as copper. An LD (Laser Diode) 10 that serves as an excitation light source for the YAG crystal 100 is provided on the surfaces of the radiator components 2a to 2f.
Each of 1a to 101f is fixed to each of the radiator components 2a to 2f in a heat conductive state.

Therefore, each of the radiator components 2a to 2f is a radiator component dividedly formed corresponding to each of the LDs 101a to 101f, that is, a part of the block radiator 2, and the heat radiation of these components is prevented. LD body components 2a-2f
By polymerizing along the alignment direction of 101a to 101f, that is, along the longitudinal direction of the YAG crystal 100, YAG
One block-shaped heat radiator 2 suitable for the crystal 100 is obtained.

Then, the cooling path 4 along the alignment direction of the LDs 101a to 101f is provided at the substantially central portion of the block-shaped radiator 2.
As shown in FIG. 1 (b), the openings are provided at both ends of the cooling path 4, more specifically, one opening of the radiator component 2a located at the outermost portion. A cooling device 3 for supplying cooling water is connected to the other portion and the other opening of the radiator component 2f as shown in FIG. 1 (a).

Although FIG. 1A shows the block-shaped radiator 2 for one unit, the YAG crystal 10 is used.
In some cases, a plurality of block-shaped radiators 2 are provided so as to surround 0. Usually, even in such a case, the number of coolers 3 is one.

Next, the structure for forming the projections for stirring the cooling water in the cooling passage 4 at a predetermined distance will be described in detail.

In FIG. 2, the projections for stirring the cooling water are formed by utilizing the circumferential grooves 5a to 5f formed in one opening of each of the radiator components 2a to 2f and the elastic annular bodies 6a to 6f. It is sectional drawing shown about the embodiment (henceforth 1st Embodiment) which did, and is equivalent to the cross section of the arrow AA part of FIG.1 (b).

In this embodiment, as shown in FIG. 2, the cooling passages 4a to 4f are provided for the respective radiator components 2a to 2f.
4 f is formed, and circumferential grooves 5 a to 5 f are formed in one opening of each of the cooling paths 4 a to 4 f, that is, the opening on the right side in FIG. 2, and annular bodies 6 a to 6 f made of elastic members are formed therein.
Are fitted in to form protrusions at predetermined intervals in the cooling passage 4.

Since the structures of the radiator components 2a to 2f are all the same, the radiator components 2a, 2a,
Only the portion 2b is taken out and its internal structure is shown in detail in FIG.

Each of the circumferential grooves 5a, 5b is formed concentrically with the cooling passages 4a, 4b of the heat dissipating component 2a, 2b on one surface of the heat dissipating component 2a, 2b, that is, on the right end face side.
The inner diameter is substantially the same as the outer diameter of the annular bodies 6a and 6b in the non-compressed state. In addition, the annular bodies 6a, 6
The inner diameter d of b is substantially the same as the inner diameters of the cooling paths 4a and 4b.

The depth t of the circumferential grooves 5a, 5b is determined by the annular bodies 6a,
It is formed to be somewhat shallower than the thickness of 6b,
As shown in FIG. 3C, when the heat dissipating element components adjacent to each other are pressure-bonded, the annular bodies 6a and 6b are elastically deformed in the thickness direction, and the inner diameters d of the annular bodies 6a and 6b are reduced,
The cooling passages 4a and 4b project toward the inner wall side. This protruding portion is a portion that functions as a protrusion for stirring the cooling water.

Therefore, by adjusting the depth t of the circumferential grooves 5a and 5b to change the compression amount of the annular members 6a and 6b, the protrusion amount of the protrusion can be freely adjusted. Further, since the annular bodies 6a and 6b themselves made of elastic members prevent the leakage of the cooling water between the radiator components 2a and 2b, it is troublesome to newly arrange a liquid leakage preventing means between the radiator components. Can also be omitted.

The annular members 6a and 6b are commercially available
A ring or the like can be used as it is.

An outline of the process of assembling the block-shaped radiator 2 when this structure is applied is shown in FIG. When assembling the block-shaped heat radiator 2, as shown in FIG. 3B, the circumferential grooves 5a-5 of the respective heat radiator constituent elements 2a-2f.
The annular bodies 6a to 6f are previously fitted and attached to f,
These heat radiator components 2a to 2f are polymerized so as to be lined up to form one block heat radiator 2, and then bolt holes 8 are formed in the outer peripheral portion of each heat radiator component 2a to 2f.
Insert the long bolt 7 into the bolt head 7,
The block-shaped radiator 2 is fastened from both ends with a and the nut 9.

In this case, the bolt holes 8, 8, 8, ... Of the respective heat dissipating body constituent elements 2a to 2f correspond to the respective heat dissipating body constituent elements 2a to 2f.
It is desirable to dispose at the four corners of 2f or at both ends of the diagonal line as shown in FIG. 1 (b).

According to the first embodiment described above, the heat radiated from the LDs 101a to 101f, which are the excitation light sources, is transferred to the block radiator 2 made of metal having high conductivity, and the block radiator is also formed. The block-shaped radiator 2 is cooled by the cooling water flowing through the cooling passage 4 provided in the hole 2.

At this time, the cooling water flowing through the cooling passage 4 is
An annular body 6a protruding into the cooling passage 4 as shown in FIG.
Since each of the protrusions formed by ~ 6f stirs to form a turbulent flow, heat is evenly transferred from the wall surface of the cooling passage 4 to the cooling water inside, and a block shape using the cooling water is formed. Cooling performance of the radiator 2, finally LD1
The cooling performance for 01a to 101f is improved.

Further, since the conventional cooler 3 itself for supplying the cooling water can be used as it is, no special facility investment is required for peripheral devices and the like.

As a result, a plurality of LDs 10 serving as excitation light sources
A huge amount of heat generated when 1a to 101f are mounted at high density can be removed at a small cost, and a high-power semiconductor laser with high power and high-quality pumping light can be realized. Further, the cooling ability of the block-shaped radiator 2 is strong, and the L
Since there is little variation in the oscillation wavelength due to a manufacturing problem of D, the oscillation wavelengths of the plurality of LDs 101a to 101f can be surely made uniform, and the YAG crystal 100 serving as a laser medium can be efficiently excited, and a high output can be obtained. With this, a stable laser can be obtained.

Further, the machining of the peripheral grooves 5a to 5f in the heat dissipating element components 2a to 2f and the annular body 6a such as an O-ring.
Since a plurality of protrusions can be formed in the cooling passage 4 by a simple assembling process such as the internal fitting of 6f and the superposition connection of the radiator components 2a to 2f by the long bolt 7 and the nut 9, the cooling device can be formed. The manufacturing process of is simplified.

At this time, a commercially available O-ring or the like can be used as the annular bodies 6a to 6f, and since the O-ring itself also serves as the liquid leakage prevention means, a special liquid leakage prevention means is used. There are also advantages such as reduction in manufacturing cost and reduction in the number of parts compared to the case where they are deployed as separate parts.

By changing the depth t of the circumferential grooves 5a to 5f and adjusting the compression amount of the annular members 6a to 6f, the inner diameter of the annular members 6a to 6f, that is, the protrusion amount of the protrusion can be adjusted. Is. Therefore, it becomes possible to easily form the protrusions corresponding to the required stirring function and perform the temperature control for adjusting the oscillation wavelength of the LDs 101a to 101f and the appropriate temperature control for cooling. Also, cooler 3
It is also possible to adjust the inner diameters of the annular bodies 6a to 6f, that is, the protrusion amount of the protrusions, depending on the pumping capacity of.

When the protrusion amount of the protrusion formed by the inner diameters of the annular bodies 6a to 6f is reduced, the peripheral groove 5a to
It suffices to further cut 5f to increase the depth t. On the contrary, if it is desired to increase the protrusion amount of the protrusion, the end faces of the radiator components 2a to 2f may be shaved. It suffices to reduce the substantial groove depth t.

It is also possible to adjust the fastening force between the long bolt 7 and the nut 9 to adjust the inner diameter of the annular members 6a to 6f, that is, the protrusion amount of the protrusion. In this case, long bolt 7
If the tightening force between the nut and the nut 9 is weakened, the protrusion amount of the protrusion decreases,
Further, if the fastening force between the long bolt 7 and the nut 9 is increased, the protrusion amount of the protrusion is increased. Note that FIG. 3C shows a state in which the end surface of the radiator component 2a and the end surface of the radiator component 2b are in complete contact with each other, and the fastening force between the long bolt 7 and the nut 9 is further strengthened. Also represents a limit state in which the protrusion amount of the protrusion cannot be increased.

Next, instead of using an elastic member such as an O-ring, the cooling path 4 in the radiator components 2a to 2f is used.
An embodiment will be described in which one of the openings a to 4f is reduced in diameter to form a protrusion for stirring cooling water.

FIG. 4D shows that a ring-shaped member having no elasticity is fitted in a circumferential groove formed in one opening of each radiator component to reduce the diameter of one opening of the cooling paths 4a to 4f. It is sectional drawing shown about embodiment (henceforth a 2nd embodiment) which formed the protrusion for cooling water stirring. In FIG. 4D, FIG.
In the cross section taken along the line A-A of (b), the radiator component 2a,
Only the portion corresponding to 2b is taken out and shown, but the structures of the other radiator components 2c to 2f are also the same.

Each of the circumferential grooves 11a and 11b for internally fitting the annular member 10b having no elasticity includes the heat dissipating element 2a,
2b cooling passages 4a, 4b and radiator 2 on the concentric circle
It is formed on one surface of a and 2b, that is, on the left end surface side, and its inner diameter is substantially the same as the outer diameter of the annular member 10b. Further, the inner diameter of the annular member 10b is formed smaller than the inner diameters of the cooling paths 4a, 4b, and the reduced diameter portion 12b forms a projection for stirring the cooling water.

In this case, since the annular member 10b itself does not have the function of preventing the leakage of the cooling water, the radiator component 2
A peripheral groove 13a, 13b for storing an O-ring is provided on the other surface of a, 2b, that is, on the right end surface side, and O-rings 14a, 14b dedicated to preventing liquid leakage are fitted therein to form a heat radiator component. It is configured to prevent the leakage of cooling water during the period.

The front shape of the annular member 10b is shown in FIG.
Further, FIG. 4B shows a state in which the annular member 10b is removed from the radiator component 2b.

The reduced diameter portion 12b of the annular member 10b is shown in FIG.
As shown in FIG. 4B and FIG. 4A, the reduced diameter portion 1
A tapered surface 15b is formed so that the diameter of the 2b increases from the axial center to both sides. The tapered surface 15b can be easily formed by using countersinking from both sides of the annular member 10b, or using other plastic working or the like.

An outline of the process of assembling the block-shaped radiator 2 when this structure is applied is shown in FIG. When assembling the block-shaped radiator 2, first, as shown in FIG. 4C, the circumferential grooves 11a, 11b, ... on the left end face side of each of the radiator components including the radiator component 2b. A ring-shaped member for each heat-radiating body component such as the ring-shaped member 10b is fitted in and attached, and the circumferential groove 13 on the right end face side of each of the heat-radiating body components such as the heat-radiating body component 2b is attached.
a, 13b, ... are o-rings 14a, 14b,
Install an o-ring for preventing liquid leakage such as.

Then, these radiator components 2a to 2
After f is polymerized to form one block-shaped radiator 2, long bolts are inserted into the bolt holes 8, 8, 8 ... Formed in the outer peripheral portions of the respective radiator components 2a to 2f. 3 (b)
Perform the same assembly work as.

By this operation, the o
The rings 14a, 14b, ... Are compressed between the radiator components to prevent the leakage of cooling water between the radiator components, and the repulsive force of the ring members 10b ,.
・ ・ Crimping and fixing to the end face of the radiator component adjacent to the right side.

Unlike the embodiment described with reference to FIGS. 3A to 3C, the hardness of the annular member 10b is high and no strong external force acts on this annular member. The initial accuracy of the reduced diameter portion 12b forming the protrusion is reliably maintained.

In this way, a plurality of radiator components 2a to 2f each having a reduced diameter portion formed by attaching the annular member for each radiator component such as the annular member 10b are arranged continuously. By superposing and performing fastening work with long bolts and nuts, the cooling passages 4a to 2f of the respective radiator components 2a to 2f are provided in the cooling passages 4 of the block-shaped radiator 2.
A reduced-diameter portion that becomes a projection for cooling water agitation is formed at a predetermined separation distance comparable to the length of 4f.

According to the second embodiment described above, it is sufficient to process only one surface of each of the radiator components 2a to 2f to provide the reduced diameter portion, so that each of the radiator components 2a to 2f can be processed. Compared with the case where the reduced diameter portion is provided in the central portion of the cooling paths 4a to 4f, the working process can be simplified.

Further, since the annular member 10b and the like constituting the reduced diameter portion can be processed independently of the radiator components 2a to 2f, the overall processing work is facilitated and high processing accuracy can be expected. There is. Then, the reduced diameter portion 12b for each radiator component including the annular member 10b.
By the action of the tapered surface 15b provided on the above, abrupt reduction and expansion of the flow passage inside the cooling passage 4 are prevented, so that the pressure rise of the cooling water is alleviated and the load of the pump in the cooler 3 is reduced. There is also an effect.

Moreover, the annular member 10b forming the reduced diameter portion
Since the rigidity of etc. is high and the initial accuracy during manufacturing is secured,
A stable turbulent flow with high reproducibility can be generated, and an effective advantage can be obtained as a function of controlling temperature or reducing absolute temperature.

Further, as shown in FIGS. 5 (a) and 5 (b), a plurality of notches 16b axially penetrating the reduced diameter portion 12b of the annular member 10b are formed at a predetermined circumferential pitch, The reduced diameter portion 12b may have a substantially fin shape to serve as a protrusion in the cooling passage 4.

As described above, by providing a large number of fin-shaped projections, the stirring ability of the cooling water flowing through the cooling passage 4 is significantly improved, and heat transfer is promoted by various vortices of various sizes generated by the stirring, and The efficient cooling function is achieved.

Next, the diameter of one of the cooling passages 4a to 4f is reduced by blind-hole machining having a diameter corresponding to the inner diameter of the cooling passage and through-hole machining having a smaller diameter than this blind hole machining. An embodiment in which a protrusion for stirring is formed will be described.

FIG. 6 (a) shows a combination of blind hole processing and small-diameter through-hole processing to reduce the diameter of one of the openings of the cooling paths 4a to 4f to reduce the diameter of the simple shape of the diameter reducing portions 17a, 17b ,. Is a cross-sectional view showing an embodiment (hereinafter, referred to as a third embodiment) in which the diameter-reduced portions 17a, 17b, ... Are used as protrusions in the cooling passage 4. In FIG. 6A, FIG.
In the cross section taken along the line A-A in FIG.
Only the portions corresponding to a and 2b are taken out and shown, but the structures of the other radiator components 2c to 2f are similar to this.

First, taking the radiator component 2a as an example,
A processing step for forming the reduced-diameter portion 17a having a simple shape will be briefly described.

In this processing step, a blind hole having a diameter corresponding to the inner diameter of the cooling passage 4a is formed in the substantially central portion of the radiator component 2a, leaving a thickness comparable to the thickness of the reduced diameter portion 17a. Then, a step of forming a through hole having a diameter smaller than the inner diameter of the cooling passage 4a is formed in the substantially central portion of the remaining portion of the blind hole.

It is also possible to perform this machining process in reverse, to machine small-diameter through-holes and then large-diameter blind holes. However, for small-diameter deep hole machining, the durability of tools such as drills is improved. Since it is required, it is generally preferable to perform large-diameter blind hole processing and then perform small-diameter through-hole processing on the remaining portion.

As a result, as shown in FIG.
The outer peripheral portion of the end surface left after the double drilling is the reduced diameter portions 17a and 17b, that is, the protrusions in the cooling passage 4.

In this embodiment, the reduced diameter parts 17a, 1
Since each of 7b is formed in a flat shape with the same thickness, a milling end mill for pocket machining with a flat tip is suitable as a tool used for blind hole machining, and with respect to through hole machining, It is possible to use a drill bit with an appropriate cutting edge angle.

Further, on the other surface of the radiator component 2a, 2b, there are circumferential grooves 13a, 13 for accommodating the O-ring.
O ring 14 dedicated to preventing liquid leakage is provided in b
A and 14b are fitted to prevent leakage of cooling water between the radiator components.

The steps for assembling the thus formed radiator components 2a to 2f to form the block radiator 2 are the same as those in the above-described embodiments.

According to the third embodiment described above, the processing is performed only on the portions of the cooling paths 4a to 4f which are originally the object of the removal processing, that is, the insides of the radiator components 2a to 2f. 4 (a) to 4 (d)
Unlike the second embodiment described with reference to FIG. 5 and the modified example described with reference to FIGS. 5A and 5B, a separate member for forming the projection (reduced diameter portion) is unnecessary. Therefore, there is an advantage that the material for manufacturing the block-shaped radiator 2 is saved.

Further, as a tool used for blind hole machining, a drill bit or the like having a cutting edge having an angle of 90 °, 60 ° C. or the like at the tip can be used. In that case,
For example, as shown in FIG. 6B, it is also possible to form the diameter-reduced portions 17a and 17b having the tapered surfaces 18a and 18b whose diameters increase from one end to the other end in the axial direction to form protrusions. Reference numerals 19a and 19b in FIG. 6 (b) are peripheral grooves for accommodating O-rings, and O-rings 14a and 14b dedicated to preventing liquid leakage are fitted therein.

According to such a configuration, it is possible to prevent at least one of the rapid reduction and expansion of the flow passage in the cooling passage 4, and from the viewpoint of overall processing, Compared to the second embodiment described with reference to FIGS. 4A to 4D and the modified example described with reference to FIGS. 5A and 5B, a protrusion (a reduced diameter portion) (2) is unnecessary, and there is an advantage that processing is easy.

In the example of FIG. 6 (b), in order to prevent the rapid reduction of the flow passage in the cooling passage 4 and mitigate the pressure rise of the cooling water, the flow direction of the cooling water supplied from the cooler 3 is changed. The direction is from left to right.

Further, the blind passages having a diameter corresponding to the inner diameter of the cooling passage 4 and the through-holes having a small diameter are used in combination to form the cooling passages 4a to 4a.
A brief description will be given of some of the modifications that can be made when a reduced diameter portion is formed in a part of f to form a projection for stirring cooling water.

First, the radiator components 2a and 2b as shown in FIG. 6B are subjected to dish fir processing from the right side in the drawing, for example, dish fir processing with tip angles of 90 ° and 60 ° C. As a result, it is possible to form a tapered surface that expands in diameter from the central portion in the axial direction toward both sides at the reduced diameter portions 17a and 17b.

The shape of the reduced diameter portions 17a and 17b thus obtained is substantially the same as the shape of the reduced diameter portion 12b as shown in FIG. 4 (d).

Further, the reduced diameter portions 17a, 1 serving as protrusions near the central portions of the cooling passages 4a to 4f (in short, positions other than the end portions).
It is also possible to form 7b.

In this case, after the blind holes are formed from the left and right sides of each of the radiator components 2a to 2f toward the center,
Through holes may be formed on the wall surface remaining in the central portion.
As apparent from the above description, by selecting an appropriate tool, the shape of this reduced diameter portion is a plane of a simple shape as shown in FIG. 6 (a), or the shape of FIG. 6 (b). It is possible to have a shape with a tapered surface on one side as shown in, and it is also possible to have a shape with tapered surfaces on both sides.

Since processing is required from both sides, the processing efficiency deteriorates, but the heat dissipating elements 2a to 2f having the same shape are formed.
In the case of manufacturing, the separation distance between the reduced-diameter portions to be the protrusions is determined by the width of the radiator components 2a to 2f, and therefore, functionally, it is described in FIG. 6 (a) or 6 (b). It is possible to achieve the same effect as that of the thing.

Next, an embodiment in which a spiral groove is formed in the cooling passage 4 (hereinafter, referred to as a fourth embodiment) will be briefly described.

FIG. 6C is a sectional view showing an embodiment in which a spiral groove is formed in the cooling passage 4. The spiral grooves 20a and 20b in the cooling passage 4a and the cooling passage 4b are, for example, after forming through holes having a diameter slightly smaller than a target diameter in the radiator components 2a and 2b as pilot holes, It can be easily realized by performing tapping processing equivalent to female thread processing, and processing by NC lathe and fully automatic work by machining center can be used. Incidentally, reference numeral 19a,
Reference numeral 19b is a peripheral groove for accommodating the O-ring, in which an O-ring 14 for forming a reduced diameter portion and preventing liquid leakage is formed.
a and 14b are fitted inside. The structures of the radiator components 2c to 2f are similar to these.

The process of assembling the heat dissipating member constituent elements 2a to 2f thus formed to assemble the block heat dissipating member 2 is the same as that in each of the above-described embodiments.

According to the fourth embodiment to which such a configuration is applied, the cooling water flowing in the cooling passage 4 is spiral groove 20a, 2
Since the turbulent flow and the swirling flow are formed by stirring with the ridges of 0b, the heat transfer performance can be significantly improved.

In the example of FIG. 6C, the O-ring 14a,
The example in which the projection is provided in the cooling passage 4 by using the reduced diameter portion formed by 14b and the projection of the spiral groove together is described . When the block-shaped radiator 2 is divided into the radiator components 2a to 2f, as described above, the length of the block-shaped radiator 2 is arbitrarily set according to the size of the YAG crystal 100 serving as the laser medium. It has the advantage of being adjustable.

Further, the spiral groove is not limited to the example shown in FIG. 6C, but can be applied to the embodiments shown in FIG. 4D, FIG. 6A, FIG. It is possible to apply the composition which used together.

Various embodiments have been described above from the viewpoint of the structure. Next, specific effects of the protrusions adopted in these embodiments will be described based on simulations.

First, as a theoretical value for verifying the heat dissipation performance of the protrusions, an experimental formula was obtained for a cooling device (hereinafter referred to as a comparative example) when there were no protrusions in the cooling passage 4. It should be noted that, except for the presence or absence of protrusions, other conditions are shown in FIG.
The same as the cooling device in the above embodiment.

Cooling water temperature (θ) and wall surface of cooling passage 4 (t1)
The temperature difference between and is expressed by equation (1). θ-t1 = Q / h / A (1) where Q is the heat quantity (W) of the heating element, and h is the heat transfer coefficient (W / m).
² K) and A are the surface area (m ² ) of the cooling passage 4, and the heat transfer coefficient h is represented by the equation (2). h = Nu × λ / de (2)

Nu is the Nusselt number, λ is the thermal conductivity (W / mk) of cooling water, de is the equivalent hydraulic diameter (m), Nusert number Nu is equation (3), and equivalent hydraulic diameter de is Formula (4)
It is represented by. Nu = 0.023 × Re ^0.8 × Pr ^0.4 Nu (3) de = 4 × D1 / D2 (4)

Here, Re is the Reynolds number, Pr is the Prandtl number of the cooling water, D1 is the cooling channel cross-sectional area (m ² ), and D2 is the cooling channel circumferential length (m). These equations are the turbulent heat transfer of developed flow and are well known empirical equations for pipe flow. Then, the Reynolds number Re is expressed by the equation (5). Re ＝ υ ・ de ・ ρ / μ ・ ・ ・ (5)

Here, υ is the cooling water flow velocity (m / s), ρ is the cooling water density (kg / m ³ ), and μ is the cooling water viscosity coefficient (Kgfs / m ^2).
× 10 ^-4 ).

In the comparative example, for example, a single LD is 3
Assuming that cooling water at 20 ° C. is cooled at a flow rate of 1 liter / min into the cooling passage 4 having an inner diameter of 4 mm and a length of 10 mm and generating heat at 0 W, the cooling water temperature θ (20
(° C) and the temperature difference between the wall surface (t1) of the cooling passage 4 are as follows. As a result, from the above empirical formula, Reynolds number = 45
93, Prandtl number = 7.09, Nusselt number is 42.8, and the heat transfer coefficient h is 7274 W / m ² K from the equation (2).

After all, the cooling water temperature θ (20 ° C.) and the cooling passage 4
Since the temperature difference from the wall temperature t1 of 2 is 24.2 ° C., the theoretical wall temperature of the comparative example having no protrusions in the cooling passage 4 is about 44 ° C.

Next, in the comparative example having no protrusions as described above, the LD mounted along the cooling passage 4 from upstream to downstream.
The temperature rise of is calculated by the empirical formula as follows. For example, assuming that there is no protrusion and the flow path length is short enough not to be affected by friction, and cooling is efficiently performed with an ideal flow (laminar flow), the thermal resistance (Rtotal) of the entire LD is
It is expressed by equation (6). Rtotal = 1 / ρ · Cp · f (6) where ρ is the density of cooling water (kg / m ³ ), Cp is the constant pressure specific heat of cooling water (J / kgK), and f is the volume flow rate (m ³ / s).

According to the comparative example, when the cooling water temperature is 20 ° C. and the flow rate is 1 liter / min, the total thermal resistance of the six parallel LDs is 0.014 ° C./W from the equation (6). To be Then, as described above, when heat is generated with the total heat amount of 180 W of all LDs, the Ls arranged from the upstream side to the downstream side of the cooling path 4 are
The temperature difference ΔT (temperature rise) of D is ΔT = 0.014 ° C / W
X180 W = 2.52 ° C. Therefore, the theoretical value of the LD temperature difference arranged upstream and downstream of the cooling passage 4 in the cooling device of the comparative example having no protrusion in the cooling passage is 2.52 ° C. It will be.

Next, the heat radiation effect when the protrusion of the present invention is provided as in the embodiment of FIG. 2 will be described. As described above, one of the objects of the present invention is to reduce the L
To reduce the absolute temperature of D to prolong its life. The second is to suppress the temperature rise of the LD in order to control the oscillation wavelength of the LD for efficient laser excitation.

Therefore, in the present embodiment, the effect obtained by providing the protrusions is based on two theoretical values (absolute temperature and temperature rise value) in the state where there are no protrusions in the cooling passage 4, and the three-dimensional thermal fluid is used. Verification was performed using a simulation method.

Theoretical values in the case of the comparative example having no protrusions in the cooling passage 4 (cooling passage wall surface temperature 44 ° C., temperature difference 2.
(5 ° C.), a total of 10 types of protrusions were modeled within the cooling channel inner diameter φ4 mm with the maximum protrusion height on one side of 1.2 mm, and the heat dissipation performance due to the difference in protrusion height was analyzed.

As a result, compared with the theoretical value (44 ° C.) of the wall temperature of the cooling passage when there is no protrusion in the cooling passage 4, under the same cooling condition (water temperature 20 ° C., flow rate 1 liter / min), one side At a projection height of 0.8 mm of about 11 ° C (3
It was shown that there is a temperature reducing effect of 2 ° C.

This result shows that the higher the protrusion, the greater the turbulent flow effect due to stirring, which promotes efficient heat transfer, and is higher than the theoretical value (44 ° C.) where there is no protrusion.
This is because the heat dissipation performance is improved. Furthermore, in the cooling device according to the present embodiment, in order to realize downsizing, the radiator component 2
Since the lengths of the cooling passages 4 are short because the a to 2f are densely mounted, the cooling water has a stable velocity (layer) without a friction of the wall surface of the cooling passages 4 and a uniform velocity distribution. Flow =
This is a speed-enhancing section), and the turbulent flow effect cannot be obtained with the basic mechanism without protrusions.

On the other hand, in the structure provided with the projections, the turbulent flow state is rapidly changed as the flow paths 4 are contracted and expanded by the locally provided projections regardless of the length of the flow path.

Fluid vortices due to irregular motion are present in the turbulent flow, and the cooling water in the cooling passage 4 located away from the wall surface of the cooling passage 4 is diffused by the diffusion action of the large and small fluid vortices. Directly reaches the wall surface of the cooling passage 4, so that the temperature of the mounted LD can be efficiently lowered.

These heat transfer phenomena are generally known as the turbulence effect. After all, by providing the protrusions as described above, the heat radiation performance can be improved (about 25%) without significantly remodeling the LD cooling structure, so that an extremely high heat radiation effect can be achieved with respect to the high output of the excitation of the LD. can get.

However, although the heat dissipation performance is improved as the height of the protrusion is increased, the pressure in the cooling passage 4 is rapidly increased when the height of the protrusion exceeds 1 mm as compared with the case without the protrusion (about 12 times). = 2.1 × 10 ⁵ Pa). Therefore, since it becomes difficult for the cooling water to flow, heat dissipation performance is deteriorated, and there is a problem in terms of reliability such as an increase in the load on the pump of the cooler 3, so that it depends on the maximum capacity of the pump of the cooler 3. It is necessary to know the height of the protrusion in advance.

According to the experimental results, the maximum capacity of the pump used was 4.4 × 10 ⁵ (Pa), but when the protrusion height was 0.8 mm, the cooling water (flow rate 1 liter / min) was supplied to the three series cooling devices.
The effect of improving the heat dissipation performance was obtained by about 25% as compared with the structure without protrusions.

Next, the optimum distance from the wall surface of the cooling passage 4 to the LD will be described for the cooling mechanism for improving the heat dissipation performance by the heat conduction from the wall surface of the cooling passage 4 to the LD.

Here, a projection formed by the reduced diameter portion 12b of the annular member 10b as shown in FIG. 5A is applied as the structure most suitable for suppressing the pressure rise of the cooling liquid and improving the heat radiation performance. The height of the protrusion is 0.8 mm
As a test, the distance between the wall surface of the cooling passage 4 and the LD was changed in five stages.

Specifically, the distance from the LD is 0.5 mm.
When the cooling path 4 is provided at the position of 1 mm and when it is 1 mm, 2 m
Comparisons were made for m, 3 mm, and 4 mm.

As a result, the shorter the distance between the cooling path 4 and the LD, the more remarkable the heat radiation performance. Of the five types of distances, the best heat dissipation performance is obtained when the separation distance is 1 mm. For example, the heat quantity of the LD was 30 W and could be lowered by about 3 ° C. as compared with the case where the separation distance was 4 mm.

Therefore, in the future, when the heat quantity of the LD alone becomes 40 W as the output power of the LD becomes higher, the reduction effect of 6 ° C. and the reduction effect of approximately 9 ° C. can be obtained at the same 60 W.

The separation distance between the cooling passage 4 and the LD is 0.
In the case of 5 mm, the amount of heat radiation escaping from the wall surface of the cooling passage 4 near the LD and the amount of heat radiation escaping from the wall surface of the cooling passage 4 in the distant portion are unbalanced. It gets expensive.

From the above, the distance between the wall surface of the cooling passage 4 and the LD is optimized, the heat is efficiently transmitted to the cooling water by the heat conduction, and the protrusion provided in the cooling passage 4 provides the stirring effect. To enhance the heat transfer to reduce the absolute temperature of the LD, and to control the temperature rise between the upstream LD and the downstream LD by various eddies of various sizes of turbulent flow generated in the cooling passage 4. Is desired.

According to the experimental results, the protrusion height is 0.8 mm,
When cooling with cooling water with a flow rate of 1 liter / min, in the case of a cooling device equipped with 6 parallel LDs with a heat amount of 180 W,
The temperature of the mount part of the upstream LD is 27.8 ° C, the temperature of the mount part of the downstream LD is 29.5 ° C, and the temperature rise is Δ.
T: 1.7 ° C. Then, the variation of the oscillation wavelengths of the six LDs was 0.5 nm or less, which was a good result.

[0139]

In the semiconductor laser cooling apparatus according to the present invention, the excitation light sources are aligned and arranged on the surface of the block heat radiator made of metal having high thermal conductivity, and the block heat radiator is arranged along the alignment direction of the excitation light sources. Since a cooling passage is bored inside and projections are formed in this cooling passage at a predetermined distance to allow the cooling water from the cooler to flow while stirring, the cooling water from the wall surface of the cooling passage to the inside cooling water The heat is evenly transferred, and the cooling performance of the cooling water is greatly improved. Further, since the conventional cooler itself for supplying the cooling water can be used as it is, there is no need to make a special capital investment for peripheral devices and the like. As a result, it is possible to remove a huge amount of heat generated when a plurality of LDs (Laser Diodes) serving as excitation light sources are mounted around the laser medium with high density, at high cost, and with high power. A high-power semiconductor laser that can obtain excitation light is realized. In addition, the cooling capacity of the cooling device is strong, and the LD
Since the variation in the oscillation wavelength of each LD is small due to the sophistication of the production technology, the oscillation wavelengths of a plurality of pumping light sources are surely made uniform, and efficient pumping of the laser medium becomes possible, resulting in high output. A stable laser can be obtained. This
In this case , the block-shaped heat radiator that constitutes the main part of the cooling device is composed of a plurality of heat radiator components that are divided and formed corresponding to the individual excitation light sources, and the circumferential groove provided between the heat radiator components is elastic. Since the annular body made of a member is fitted in and compressed from both sides so that the inner diameter is reduced to form the protrusions, processing of the circumferential groove in the radiator component and internal fitting of the annular body and the radiator The protrusions can be formed in the cooling passage by a simple manufacturing process such as superposition connection of the components. A commercially available material such as an O-ring can be used as the annular body made of an elastic member, and since the O-ring itself also serves as the liquid leakage prevention means of the block-shaped radiator, a special liquid leakage prevention means is used. It is possible to provide an inexpensive cooling device that does not require it. Furthermore , it is possible to adjust the inner diameter of the annular body, that is, the protrusion amount of the protrusion by changing the depth of the circumferential groove or the pressing force to adjust the compression amount of the annular body. It is possible to easily form protrusions corresponding to the stirring function and perform temperature control for adjusting the oscillation wavelength and appropriate temperature control for cooling.
Similarly, the inner diameter of the annular body can be adjusted according to the pumping capacity of the cooler. Moreover, since one block-shaped radiator is constructed by superposing a plurality of radiator components that are divided and formed corresponding to each excitation light source, it is easy to change the number of combinations of radiator components. The work makes it possible to arrange the pumping light source according to the size of the laser medium and the like.

[0140]

[0141] In addition, it was divided and formed corresponding to the excitation light source.
Arrangement of excitation light sources by providing multiple radiator components and reducing the diameter of one opening of the cooling path in each radiator component
The block-shaped heat radiator can be fixed by polymerizing and fixing along the direction.
And the cooling path inside the block-shaped heat radiator.
The block-shaped heat radiator is easy to manufacture because it is configured to form the protrusions having the distance .

The reduced diameter portion in the cooling passage of the radiator component can be achieved by attaching an annular member having an inner diameter smaller than the inner diameter of the cooling passage. In this case, since the annular member forming the reduced diameter portion can be processed independently of the radiator component, there is an advantage that the entire processing operation becomes easy.

Further, it is possible to construct a reduced diameter portion to be a protrusion by using blind hole processing having a diameter corresponding to the inner diameter of the cooling passage and through hole processing having a small diameter. Since the processing is performed only on the inside of the heat dissipating component, the advantage that the material for manufacturing the heat dissipating component is saved.

Further, by forming a taper surface that expands from the central portion toward both sides or a taper surface that expands from one end toward the other end in the reduced diameter portion, it is possible to rapidly reduce the flow path in the cooling passage. Expansion can be prevented, and the load on the pump in the cooler can be reduced.

Furthermore, if notches are formed in the reduced diameter portion at a predetermined circumferential pitch, fluid vortices of various sizes are generated by stirring the cooling water, heat transfer is promoted, and a more efficient cooling function is provided. To be achieved.

[0146]

[Brief description of drawings]

FIG. 1 (a) is a plan view showing an embodiment in which a plurality of radiator components are superposed and fixed to form one block-shaped radiator, and FIG. 1 (b) is FIG. 1 (a). FIG. 4B is a perspective view showing only the block-shaped radiator in a simplified manner.

FIG. 2 is a sectional view showing a first embodiment in which a projection for stirring cooling water is formed by using a circumferential groove and an elastic annular body.

3 (a) is a sectional view showing the structure of the heat dissipating component of the first embodiment, FIG. 3 (b) is a sectional view showing the assembling process, and FIG. 3 (c) is the assembled state. It is sectional drawing shown about the state of.

FIG. 4A is adopted in a second embodiment in which a ring-shaped member having no elasticity is fitted in a circumferential groove formed in an opening of each radiator component to form a protrusion for cooling water agitation. 4B is a sectional view showing the annular member adopted in the same embodiment, and FIG. 4C is a sectional view showing the assembling process of the same embodiment. 4D is a sectional view showing a state after assembly.

FIG. 5 (a) is a front view showing an annular member adopted in a modified example of the second embodiment, and FIG. 5 (b) is a sectional view showing the annular member.

FIG. 6 (a) is a cross-sectional view showing a third embodiment in which a reduced diameter portion is formed by blind hole processing and small-diameter through hole processing to form a protrusion in a cooling passage, FIG. 6 (b). Is a sectional view showing a modified example thereof, and FIG. 6C is a sectional view showing a fourth embodiment in which a spiral groove is formed in the cooling passage.

FIG. 7 is a conceptual diagram showing an outline of a configuration of a conventional semiconductor laser cooling device.

[Explanation of symbols]

1 Semiconductor laser cooling device 2 Block-shaped radiator 2a to 2f Heat radiator component 3 cooler 4 Block-shaped radiator cooling path 4a-4f Cooling path for each radiator component 5a-5f circumferential groove 6a to 6f Annular body (projection) 7 Long bolt 7a bolt head 8 bolt holes 9 nuts 10b annular member 11a, 11b Circumferential groove (for internal fitting of annular member) 12b Reduced diameter part (projection) 13a, 13b circumferential groove (for O-ring storage) 14a, 14b O-ring (dedicated for liquid leakage prevention) 15b Tapered surface 16b cutout 17a, 17b Reduced diameter part 18a, 18b Tapered surface 19a, 19b circumferential groove (for O-ring storage) 20a, 20b spiral groove 100 YAG crystal as laser medium 101a-101f Semiconductor laser as excitation light source 102a-102d radiator 103a-103d Cooling path 104 cooler 105a-105d valve 106a-106d heat transfer member 107 temperature sensor

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References Japanese Patent Laid-Open No. 1-160076 (JP, A) Japanese Patent Laid-Open No. 10-294513 (JP, A) Fukui Sho 64-8740 (JP, U) Special Table 2000-500291 (JP, A) Special table H11-510962 (JP, A) Special table H11-504767 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) H01S 5/00-5 / 50 H01L 23/34-23/46 H01S 3/094

Claims (8)

(57) [Claims] 1. A cooling device for a semiconductor laser, which cools a plurality of pumping light sources arranged in parallel around a laser medium, comprising a metal having a high thermal conductivity, which is divided and formed corresponding to each pumping light source. Providing a plurality of radiator components,
A cooling path is formed along each of the radiator components along the alignment direction of the excitation light source , and each radiator component
A peripheral groove is formed in at least one opening of the cooling passage.
A ring-shaped body made of an elastic member is fitted into the ring-shaped body, and
Fixed by superposing the components along the alignment direction of the excitation light source
Together constituting the block-shaped heat radiator by the ring
Elastic by compressing each of the shaped bodies by the radiator components on both sides
Predetermined separation by deforming and reducing the inner diameter of the annular body
Distance projections are formed in the cooling path inside the block-shaped radiator
And the semiconductor laser of the cooling apparatus characterized by connecting the opening portions at both ends of the cooling path of the block-shaped heat radiator to the cooler for cooling water supply. 2. A plurality of lasers arranged in parallel around a laser medium.
It is a semiconductor laser cooling device that cools the pumping light source of
Te, a plurality of the radiator elements which are separately formed to correspond to each of the excitation light source is provided, wherein in each of the radiator elements
A cooling path is formed along the alignment direction of the excitation light source ,
One opening of the cooling path in each radiator component is reduced in diameter, and the plurality of radiator components are polymerized and fixed along the alignment direction of the excitation light source to fix the radiator in block form.
The block-shaped heat-dissipating body is formed by forming protrusions of a predetermined distance in a cooling path inside the block-shaped heat-dissipating body.
Connect the openings at both ends of the cooling channel to the cooler for supplying cooling water
A semiconductor laser cooling device characterized by the above . 3. The opening of at least one of the cooling passages in each of the radiators is formed with a circumferential groove, and an annular member having an inner diameter smaller than the inner diameter of the cooling passage is fitted thereinto to form the one opening. claims, characterized in that the parts were reduced in diameter to
2. A semiconductor laser cooling device according to 2. 4. The method of claim 2, characterized in that reducing the diameter of the opening of the one by the small-diameter through-hole drilling than blind drilled and該盲drilling of diameter corresponding to the inner diameter of the cooling passage
A cooling device for the semiconductor laser described. 5. A reduced diameter portion of the one opening, according to claim 2, claim, characterized in that a tapered surface whose diameter increases toward the both sides from the central portion in the axial direction of the fused diameter 3 or contract
The cooling device for a semiconductor laser according to any one of claim 4 . 6. A reduced diameter portion of the one opening, according to claim 2, claim, characterized in that a tapered surface whose diameter increases toward the other end from the one axial end of the fused-diameter portion 3 or bill
Item 5. A semiconductor laser cooling device according to any one of items 4 . 7. A reduced diameter portion of the one opening, according to claim 2, characterized in that forming a plurality notches extending through the said reduced diameter portion in the axial direction at a predetermined circumferential pitch, claim 3 , Claims
4. A cooling device for a semiconductor laser according to any one of claims 4 and 5 . 8. An o-ring is provided between the plurality of heat dissipator constituent elements to form a liquid leakage prevention means.
Claim 2, Claim 3, Claim 4, Claim 5, Claim 6
Alternatively, the semiconductor laser cooling device according to claim 7 .