JP2002280661A - Light source constituted of laser diode module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light source having a plurality of laser diode modules in which optical wavelengths are not changed, which are arranged with high density and have high optical outputs. SOLUTION: The light source is constituted of a plurality of the laser diode modules that have metallic substrates mounted with laser diode chips and optical units and have Peltier elements which are thermally connected to the metallic substrates arranged with high density and have high optical output, of a mounting part mounting a plurality of the laser diode modules, and of a plurality of heat pipes whose heat absorbing parts are thermally connected to the Peltier elements. A plurality of the laser diode modules and a plurality of the heat pipes are arranged so that the temperature of the laser diode modules become uniform.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high power light source, and more particularly, to a light source comprising a plurality of laser diode modules of high light output arranged at a high density.

[0002]

2. Description of the Related Art Generally, a laser diode module is
It is used as a signal light source for optical fiber communication, especially for trunk line and CATV, and as an excitation light source for fiber amplifiers. Such a laser diode module incorporates a Peltier element in order to realize high output and stable operation, and optical components such as a laser diode chip, a photodiode chip, and a lens are mounted on a metal substrate mounted on the Peltier element. , Electrical components such as thermistor elements, inductors, and resistors. Note that the above-described Peltier element is a thermoelectric semiconductor. When a DC current flows, in the case of a p-type semiconductor, heat is transferred in the direction in which the current flows, and in the case of an n-type semiconductor, the direction is opposite to the current. Is transferred to the thermoelectric semiconductor, and a temperature difference occurs on both sides of the thermoelectric semiconductor. The cooling system using the Peltier element uses the above-mentioned temperature difference to cool the low temperature side,
The high temperature side is used for heat dissipation.

[0003] The laser diode module detects the temperature of the chip by means of a thermistor element adhered to the vicinity of the above-mentioned laser diode chip. By driving the Peltier element by feeding back the detected temperature value in this way, the entire metal substrate on which the laser diode chip is disposed is cooled, and the temperature of the laser diode chip is kept constant.

FIG. 4 shows a conventional laser diode module. FIG. 4 shows a schematic sectional view of the laser diode module. As shown in FIG. 4, the laser diode module includes a mount 113 on which a laser diode chip 111 and a heat sink 112 are mounted, a chip carrier 115 on which a monitoring photodiode chip 114 is mounted, a lens holder 116, a resistor (not shown), Metal substrate 1 with inductor, circuit board, etc. bonded
10 a and a Peltier element 7. The Peltier element is fixed on the package heat dissipation plate 118 with metal solder. Note that ceramic plates 119A and 119B are arranged above and below the Peltier element 117.

FIG. 5 is a sectional view of the laser diode module taken along the line AA 'in FIG. As shown in FIG.
The main part of the laser diode module has a thermistor 121 mounted on a heat sink 112 in addition to the laser diode chip 111, and a Peltier element 117 and a metal substrate 1.
A soft solder 122 is used as a metal solder for bonding with 10a in order to reduce the difference in thermal expansion between the two.
The above-mentioned metal substrate is usually made of copper tungsten (CuW:
(A copper weight distribution ratio of 10 to 30% exists). For the bonding between the metal substrate and the Peltier element, a low-temperature soft solder such as indium tin (InSn) has been used in order to reduce the difference in thermal expansion between the two.

However, in recent years, as the output of the laser diode module has been increased, the requirements for the cooling ability and the reliability of the temperature environment (that is, the ability to continue functioning normally even when the temperature changes) have become severe. Has become. First, in order to improve the cooling capacity, it is necessary to increase the size of the Peltier element or to make the metal substrate mounted on the upper part a material having high thermal conductivity. ), The temperature stress on the metal substrate mounted on the Peltier element increases. Therefore, the influence of the difference in the coefficient of thermal expansion between the Peltier element and the metal substrate increases, and a problem arises in that cracking occurs due to sliding of a soft solder for bonding the two. In addition, the solder creep phenomenon peculiar to soft solder becomes remarkable, so that the solder for bonding the Peltier element to the metal substrate is made of bismuth tin (B
It is necessary to use a low-temperature hard solder such as iSn).

In order to solve the above-mentioned problems, Japanese Patent Application Laid-Open No. Hei 10-200208 discloses a semiconductor laser module having a metal substrate made of two kinds of metal materials.
FIG. 6 shows the outline. As shown in FIG. 6A, in the semiconductor laser module, a metal that mounts an LD chip 201 and a thermistor 211 for keeping the LD chip at a constant temperature via a heat sink 202 and a submount 203 together with an optical lens. A substrate 210 and a Peltier element 207 having ceramic substrates 209A and 209B on the upper and lower surfaces are bonded to each other with a hard solder 212.

[0008] This metal substrate 210 is
Is bonded to the upper surface of the Peltier element 207 in a direction perpendicular to the direction in which the heat flow from the Peltier element 207 is directed. In particular, the metal substrate 210 is formed such that the first metal member 213 is disposed at the center of the substrate including immediately below the LD chip 201, and the second metal member 214 is disposed around the side surface thereof. Further, as shown in FIG. 6B, in the metal substrate 210, the first metal member 213 is formed of a metal material having a high thermal conductivity, and the second metal member 214 is formed more than the first metal member 213. It is formed of a metal material having a small coefficient of thermal expansion.

That is, by using the metal substrate 210 described above, the thermal expansion of the entire metal substrate is reduced, the heat conduction is improved, and the cooling performance is improved.
We hope to increase the reliability of Peltier devices. It should be noted that a plurality of laser diode modules, which are optical output sources, are usually mounted on the optical excitation light source or the optical signal light source. Laser diode modules are used in optical amplifiers in combination with other optical components.

[0010]

According to the prior art described above, it is expected that the cooling performance of the Peltier device and the reliability of the Peltier device in each laser diode module will be improved. However,
Each laser diode module has higher output,
If a large number of laser diode modules with higher output are arranged and used at a high density, the thermal conductivity of the metal substrate disposed between the chip and the Peltier element can be increased, and the difference in the coefficient of thermal expansion can be reduced. Simply reducing the size of the laser diode module cannot increase the output of the laser diode modules and cannot deal with the heat generated due to the high density of the arrangements, thus causing a problem that the function of the laser diode module is damaged.

That is, when each laser diode module itself is small in size and has a high heat generation density, and is used as a light pumping light source or an optical signal light source which requires mounting a plurality of such laser diode modules, It was difficult to dissipate the heat. On the other hand, a light pumping light source or an optical signal light source is required to further improve the optical output. In the conventional method, the cooling by the Peltier device of the laser diode module reaches its limit, and the performance of the semiconductor device is fully utilized by 100%. It can only be used if it cannot be used.

Further, there is a need in the market to maintain the power consumption due to the excitation of the Peltier element and the semiconductor element at the same level or less even if the light output is improved, and the heat radiation characteristic in the light source is very important. It has become to.
Further, when a temperature difference occurs between the individual laser diode modules or a temperature difference occurs around the laser diode module, the optical components are deformed because the thermal expansion coefficients of the optical component and the components around the optical component are different.
The above-mentioned deformation causes a change in the wavelength of the laser, which causes a serious problem that the performance as a light source is deteriorated.
As described above, the emergence of a light pumping light source or a light signal light source with high light output mounted on a heat sink having excellent heat dissipation performance is expected.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve the conventional problems and to provide a light source comprising a plurality of laser diode modules arranged at a high density and having a high light output without causing a change in light wavelength or the like. Is to do.

[0014]

Means for Solving the Problems The present inventor has made intensive studies to solve the above-mentioned conventional problems. as a result,
Conventionally, the use of a single crystal diamond, which has been rejected because it incorporates a liquid called hydraulic fluid, has been associated with the adverse effects of leakage of hydraulic fluid and moisture, and has been hated for use in highly precise equipment such as laser diode modules. By connecting a heat pipe having a thermal conductivity of about 20 times or more to the Peltier device, the risk of destruction of the Peltier device is significantly reduced, and the output of the laser diode module is increased, and the high density arrangement of the laser diode modules is achieved. Was found to be able to respond sufficiently.

That is, each of the Peltier devices of the laser diode module including the metal substrate on which the laser diode chip and the optical device are mounted, and the Peltier device thermally connected to the metal substrate, further absorbs heat from the heat pipe. When the parts are thermally connected, the individual laser diode modules can be cooled to an unprecedented degree even if a large number of laser diode modules are arranged at a high density, even if the individual light output is high. It has been found that it is possible to provide a highly reliable light source composed of a plurality of laser diode modules with high light output.

Further, when the laser diode module and the heat pipe are arranged so as to eliminate the temperature difference between the plurality of laser diode modules, the temperature of each laser diode module becomes uniform, and the temperature around the laser diode module becomes higher. Since the environment is uniform, it has been found that characteristics unique to the light source, that is, a desired light wavelength can be kept constant, and a light source with high performance can be obtained.

The present invention has been made based on the above findings, and a first aspect of a light source comprising a laser diode module according to the present invention is a metal substrate on which a laser diode chip and an optical device are mounted, respectively. and,
A plurality of laser diode modules having a high light output and arranged at a high density, including a peltier element thermally connected to the metal substrate, a mounting part for mounting the plurality of laser diode modules, and the peltier element To
A plurality of heat pipes to which a heat absorbing portion is thermally connected, and the laser diode module and the plurality of heat pipes are arranged such that the respective temperatures of the laser diode module become uniform. , A light source comprising a laser diode module.

According to a second aspect of the light source comprising the laser diode module of the present invention, each of the plurality of laser diode modules is located at an equal distance from a near end of the mounting portion, and the size of the heat pipe is reduced. A light source comprising a laser diode module, wherein the light source has the same length and the same temperature.

A third aspect of the light source comprising a laser diode module according to the present invention is a light source comprising a laser diode module, wherein the mounting portion is formed of a parallelogram or a parallelogram. .

A fourth aspect of the light source comprising a laser diode module according to the present invention is a light source comprising a laser diode module, wherein the heat pipe is thermally connected to each of the laser diode modules.

According to a fifth aspect of the light source comprising the laser diode module of the present invention, the mounting portion on which the plurality of laser diode modules are mounted has a hole for accommodating a heat absorbing portion of the heat pipe, and The light source is a laser diode module provided along the longitudinal direction of the diode module, wherein the heat pipe housed in the hole and the laser diode module are thermally connected.

According to a sixth aspect of the light source comprising the laser diode module of the present invention, the heat pipe comprises a round heat pipe, and a heat radiating fin is provided on a heat radiating portion of the round heat pipe. , A light source comprising a laser diode module.

According to another aspect of the light source comprising the laser diode module of the present invention, the bottom surface of the laser diode module has a curved surface portion, and the round heat pipe is closely connected to the curved surface portion. This is a light source composed of a laser diode module.

Another aspect of the light source comprising the laser diode module of the present invention is a light source comprising a laser diode module, wherein another radiating fin is provided on the bottom surface of the mounting portion.

Another aspect of the light source comprising a laser diode module of the present invention is a light source comprising a laser diode module, wherein the light source is a light excitation light source in an optical transmission system.

Another embodiment of the light source comprising a laser diode module according to the present invention is a light source comprising a laser diode module, wherein the light source is a light source for an optical signal in an optical transmission system.

One embodiment of the Raman amplifier of the present invention is as follows.
A Raman amplifier using a light source comprising the laser diode module.

[0028]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a light source comprising a laser diode module according to the present invention will be described in detail with reference to the drawings. FIG. 1 is a diagram showing an outline of an example of each laser diode module constituting a light source according to the present invention. As shown in FIG. 1, the laser diode module 10 includes a semiconductor laser 11, a first lens 12, a second lens 13, an expanded core fiber 14, and an airtight case 20.
It has. The semiconductor laser 11 is provided on a base 21 via a chip carrier 22 at a predetermined distance from the first lens 12. The base 21 is disposed above a Peltier element 23 for temperature control provided in the airtight case 20. The base 21 is a composite material whose main part is made of copper and whose part where the first lens 12 is installed is made of stainless steel. The carrier 24 is fixed to the base member 21 on the side facing the first lens 12 with the chip carrier 22 interposed therebetween, and a monitoring photodiode 24 a is provided at a position of the carrier 22 facing the semiconductor laser 11.

The first lens 12 has a collimator lens 12b held by a lens holder 12a. The lens holder 12a is fixed to the base 21 by welding. As the collimator lens 12b, an aspheric lens is used to obtain high coupling efficiency. The second lens 13 holds a spherical lens 13b whose upper and lower portions are cut out by a lens holder 13a. The position of the lens holder 13a is adjusted in a plane perpendicular to the optical axis, and
a.

The core-enlarged fiber 14 is polished obliquely at the tip end where the core is enlarged at an angle of 6 ° with respect to the optical axis, and the polished surface is coated with an anti-reflection coating. Being protected. The metal cylinder 15 is welded and fixed to an optimum position of the adjustment member 16. The metal tube 15 is slid in the front-rear direction along the optical axis direction of the core enlarged fiber 14 in the adjustment member 16,
By rotating around the optical axis, the adjustment member 16 is adjusted to the optimum position.

A light source comprising a laser diode module according to the present invention is arranged at high density, each including a metal substrate on which a laser diode chip and an optical device are mounted, and a Peltier element thermally connected to the metal substrate. A plurality of laser diode modules with high light output, a mounting portion for mounting the plurality of laser diode modules, and a plurality of heat pipes to which the heat absorbing portion is thermally connected to the Peltier element, and This is a light source including a laser diode module, in which the laser diode module and a plurality of heat pipes are arranged so that the respective temperatures of the laser diode module become uniform. Each of the plurality of laser diode modules described above is located equidistant from the near end of the mounting portion, and the heat pipes are the same in size and length, and as a result,
The temperature of each of the laser diode modules is uniform.

FIG. 2 is a top view showing one embodiment of a light source comprising a laser diode module according to the present invention. As shown in FIG. 2, in this embodiment, the mounting portion 3
0, eight laser diode modules 10 are arranged, and the heat absorbing portions of the round heat pipes 32, 33 are thermally connected to each of the laser diode modules 10, and the round heat pipes 32, 33 The radiation fins 34 and 35 are attached to the radiation part. That is, four laser diode modules 10 are arranged in parallel with each other at positions near two ends of the rectangular mounting portion. The laser diode module 10 is located at a predetermined distance a, b from each end. Adjacent laser diode modules 10 are separated from each other by a predetermined distance to form two laser diode module groups each including four laser diode modules parallel to the long axis of the mounting portion. By arranging the laser diode modules 10 in this manner, a high-density laser diode module can be arranged.

In the light source of the present invention, a plurality of laser diode modules and a plurality of heat pipes are arranged so that the respective temperatures of the laser diode modules become uniform. That is, the individual laser diode modules 10 forming one set of the two laser diode module groups have the same distance a from one end.
It is located in. A heat absorbing portion of a heat pipe 32 of the same size (diameter and length) and of the same material is thermally connected to the laser diode module 10, and the same material and the same size are provided at the same position of the heat radiating portion of the heat pipe 32. Are connected.

The individual laser diode modules 10 forming another set of the two sets of laser diode modules are located at the same distance b from the other end.
A heat pipe 33 of the same size (diameter and length) and of the same material is thermally connected to the laser diode module 10, and a radiating fin of the same material and the same size is placed at the same position of the heat radiating portion of the heat pipe 33. 35 are connected. Preferably, the distances a and b from the ends are the same. Further, the heat pipes 32 and 33 are preferably made of the same material having the same size (diameter and length). Further, the radiation fins 34,
35 are preferably the same material and the same size.

As described above, by arranging the laser diode module, the heat pipe, and the radiation fin, the temperature difference between the plurality of laser diode modules is eliminated, and the temperature environment around the laser diode module is made uniform. And as a result,
A constant wavelength can be maintained. The arrangement density of the laser diode modules can be as high as physically possible. That is, it is possible to arrange not only in the horizontal plane but also in the vertical direction.

FIG. 3 is a top view showing another embodiment of a light source comprising a laser diode module according to the present invention.
As shown in FIG. 3, in this embodiment, eight laser diode modules 1 are mounted on a regular octagonal mounting portion 31.
0 is disposed, and the heat absorbing portion of the round heat pipe 32 is thermally connected to each laser diode module 10,
Further, a radiation fin 34 is attached to a radiation part of the round heat pipe 32. That is, the laser diode module 1 is located at a position near each side of the mounting portion 31 having a regular octagon.
0 is arranged. Laser diode module 10
Are located at a predetermined distance a from each end. The adjacent laser diode modules 10 are located at the same distance from the ends of the corresponding sides, so that a high-density laser diode module can be arranged.

Also in the light source of the present invention, the temperature of the laser diode module is made uniform so that
A plurality of laser diode modules and a plurality of heat pipes are arranged. That is, the individual laser diode modules 10 are located at the same distance a from the end of each side of the regular octagon. A heat absorbing portion of a heat pipe 32 of the same size (diameter, length) and of the same material is thermally connected to the laser diode module 10, and the same material and the same size are placed at the same position of the heat radiating portion of the heat pipe 32. Are connected.

As described above, by arranging the laser diode module, the heat pipe, and the radiation fin, the temperature difference between the plurality of laser diode modules is eliminated, and the temperature environment around the laser diode module is made uniform. And as a result,
A constant wavelength can be maintained. The arrangement density of the laser diode modules can be as high as physically possible. That is, it is possible to arrange not only in the horizontal plane but also in the vertical direction.

In order to enhance the heat radiation effect of the laser diode module, it is preferable to shorten the distance of heat transfer, and it is preferable that each laser diode module is located as close as possible to each end. As a result, the heat pipe can be shortened. Further, the diameter of the heat pipe can be reduced. Accordingly, the thickness of the mounting portion (that is, the thickness of the heatsink base plate) can be reduced, so that the thickness of the light source can be reduced and made compact.

The heat pipe is generally provided with a container having a sealed cavity, and heat is transferred by phase transformation and movement of the working fluid contained in the cavity. Some of the heat is directly transmitted through the material of the container constituting the heat pipe, but most of the heat is transferred by phase transformation and movement by the working fluid. On the heat absorbing side of the heat pipe to which the cooling component is attached, the heat transmitted through the material of the container forming the heat pipe evaporates the working fluid, and the vapor moves to the heat radiation side of the heat pipe. On the heat radiation side, the working fluid vapor is cooled and returns to the liquid state again. The working fluid that has returned to the liquid phase moves to the heat absorbing side again. Heat is transferred by such phase transformation and movement of the working fluid.

The heat pipe 31 may be a round heat pipe. That is, as shown in FIG. 1, each of the laser diode modules has a metal substrate 21 on which a laser diode chip 11 and an optical device 12 are mounted, and a Peltier device 2 thermally connected to the metal substrate 21.
The Peltier element 23 is further connected to a heat absorbing portion of a heat pipe 31.

In the light source comprising the laser diode module of the present invention, as described above, the heat pipes 32, 3
3 are thermally connected. Although not shown, in the light source including the laser diode module of the present invention,
A hole for accommodating the heat absorbing portion of the heat pipe is provided in the mounting portion 30 on which the plurality of laser diode modules 10 are mounted, and the heat pipe is provided along the longitudinal direction of the laser diode module and accommodated in the hole. 32,
33 and the laser diode module 10 are thermally connected.

The hole for accommodating the heat pipe is drilled, and the inner surface of the hole is plated with a metal such as tin or gold having good wettability with solder. The surface of the heat pipe inserted into the hole is pre-plated with the same metal as described above, which is good for solder bonding. The heat pipes 32 and 33 thus plated are inserted into the holes and soldered. As a result, the air layer that increases the thermal resistance can be completely removed, and the thermal resistance can be reduced. If any air layer remains between the heat pipe and the hole,
A heat insulating layer is locally formed, the thermal resistance is increased, and the heat transport performance of the heat pipe is significantly reduced.

Further, in the light source comprising the laser diode module of the present invention, the bottom surface of the laser diode module has a curved surface, and a round heat pipe is closely connected to the curved surface. Although not shown,
Since the bottom of the laser diode module 10 is processed so as to enter the inside of the mounting section 30 and the bottom has a curved surface, the laser diode module 10
The bottom of the heat pipe 32 inserted in the mounting part 30,
33 are closely connected in a state of directly contacting the surface.

Further, on the back surface (that is, the bottom surface) of the mounting portion 30 on which a plurality of laser diode modules are mounted,
Another heat radiation fin may be provided. In this way, by providing another radiating fin on the bottom surface of the mounting portion, the heat generated from the laser diode modules arranged at a high density is quickly transferred to the radiating side by the heat pipes 32 and 33. The heat is radiated to the atmosphere by the radiating fins, and part of the heat is directly radiated to the atmosphere by another radiating fin disposed on the bottom surface of the mounting portion. Therefore,
Even if the light output of each laser diode module is further increased and the laser diode modules with high light output are arranged at a high density, the heat of the laser diode module is efficiently radiated and arranged inside the laser diode module. The maintained Peltier element can be maintained within a predetermined temperature range without deteriorating the performance of the laser diode chip 11 without deteriorating the performance of the laser diode chip 11, and the performance of the light source can be maintained. At this time, a temperature difference is prevented from occurring between the individual laser diode modules.

The material of the mounting portion is preferably aluminum. The heat pipe is preferably a copper round heat pipe, and water can be used as the working fluid. A wick may be arranged in the heat pipe to facilitate the reflux of the working fluid. The shape of the round heat pipe may be circular, elliptical, flat, or the like.

The light source comprising the laser diode module of the present invention is used as a light pumping light source in an optical transmission system. Further, the light source including the laser diode module of the present invention is used as a light source for an optical signal in an optical transmission system. Further, the Raman amplifier of the present invention is a Raman amplifier using a light source comprising the laser diode module of the present invention.

[0048]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A light source comprising a laser diode module according to the present invention will be described with reference to embodiments. As shown in FIG. 2, a mounting portion made of aluminum and having a length of 130 mm × a width of 190 mm × a thickness of 20 mm was prepared. Next, four holes for accommodating the heat pipes at predetermined intervals in the center of the mounting portion were formed on both sides of the mounting portion along the lateral direction of the mounting portion. The inner surface of the hole was plated with tin. The surface of the heat pipe inserted into the hole is pre-plated with the same metal as described above, which is good for solder bonding. A copper round heat pipe having an outer diameter of 6.35 mm was prepared, and the surface of the heat pipe inserted into the hole was plated with tin. Next, the heat radiating part of the heat pipe was inserted into the hole, and the heat pipe and the mounting part were soldered.

A concave portion for accommodating the bottom of the laser diode module was formed in a portion of the upper surface of the mounting portion where the laser diode module was disposed. At the bottom of the laser diode module, a curved surface is formed,
The bottom of the laser diode module was in direct contact with the outer surface of the heat pipe via the heat transfer grease.

As shown in FIG. 2, the heat radiating portions of four round heat pipes extending in parallel to the mounting portion from both sides of the mounting portion where the laser diode modules are arranged are provided as shown in FIG. A plate-shaped heat radiation fin having a length of 180 mm, a width of 40 mm and a thickness of 0.3 mm was attached.

In addition, on the mounting portion, as shown in FIG.
Four laser diode modules, a total of eight, were arranged at a position 2 mm from each end. The light output of each laser diode module was 100 mW or more. Water is sealed in the heat pipe as working fluid,
A wire-like wick is arranged.

When the light source comprising the laser diode module of the present invention thus manufactured was operated, a high light output of 300 mW could be obtained, and the laser diode module was operated in a temperature range of 24.9 to 25.1 ° C. The temperature inside was able to be maintained. As described above, since the round heat pipe and the mounting portion are metal-bonded such that the round heat pipe directly contacts the bottom of the laser diode module, high heat radiation characteristics can be obtained. Therefore,
An optical excitation light source or an optical signal light source that is compact and maintains a high optical output can be realized with low power consumption.

Further, since the laser diode modules are arranged at the same distance from the respective ends and the heat pipes and the radiation fins of the same size and material are closely connected, the temperature difference between the individual laser diode modules is reduced. A constant wavelength was maintained without occurrence of, and a light source with high performance was obtained.

[0054]

As described above, according to the present invention, it is possible to provide a light source comprising a plurality of laser diode modules which are arranged at a high density and have a high light output without causing a change in light wavelength or the like. An optical excitation light source or an optical signal light source that is compact and has a high optical output can be provided with low power consumption, and is highly useful in industry.

[Brief description of the drawings]

FIG. 1 is a diagram showing an outline of an example of a laser diode module constituting a light source according to the present invention.

FIG. 2 is a top view showing one embodiment of a light source including a laser diode module according to the present invention.

FIG. 3 is a top view showing another embodiment of a light source including a laser diode module.

FIG. 4 is a schematic view showing a conventional laser diode module.

FIG. 5 is a sectional view of the laser diode module taken along line AA ′ in FIG. 4;

FIG. 6 is a diagram showing a conventional semiconductor laser module provided with a metal substrate made of two kinds of metal materials.

[Explanation of symbols]

 10. Laser diode module 11. Semiconductor laser 12. First lens 13. Second lens 14. Core expanded fiber 15. Metal tube 1. Adjusting member 20. Airtight case 21. Base 22. Chip carrier 23. Peltier device 24. Carrier 30. Mounting part 31. Mounting unit 32. Heat pipe 33. Heat pipe 34. Heat radiation fins 35. Radiation fin

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Shinya Nagamatsu 2-6-1 Marunouchi, Chiyoda-ku, Tokyo Inside Furukawa Electric Co., Ltd. (72) Koichi Murata 2-6-1, Marunouchi, Chiyoda-ku, Tokyo F-term in Furukawa Electric Co., Ltd. (reference) 5F073 EA03 EA24 FA02 FA07 FA08 FA25 FA26 FA30

Claims (6)

[Claims] A plurality of high-density, high-light-output, metal-substrates each having a laser diode chip and an optical device mounted thereon, and a Peltier element thermally connected to the metal substrate. A laser diode module, a mounting portion for mounting the plurality of laser diode modules, and a plurality of heat pipes to which the heat absorbing portion is thermally connected to the Peltier element; and A light source comprising a laser diode module, wherein the plurality of laser diode modules and the plurality of heat pipes are arranged so that the temperature of the plurality of laser diode modules becomes uniform. 2. The laser diode module according to claim 1, wherein each of said plurality of laser diode modules is located equidistant from a near end of said mounting portion, and said heat pipes have the same size and length. 2. The light source comprising the laser diode module according to claim 1, wherein the respective temperatures are uniform. 3. The light source comprising a laser diode module according to claim 2, wherein said mounting portion is formed of a parallelogram or a parallelogram. 4. A light source comprising a laser diode module according to claim 1, wherein said heat pipe is thermally connected to each of said laser diode modules. 5. A mounting portion on which the plurality of laser diode modules are mounted, wherein a hole for accommodating a heat absorbing portion of the heat pipe is provided along a longitudinal direction of the laser diode module. The light source comprising the laser diode module according to claim 4, wherein the heat pipe housed in the hole and the laser diode module are thermally connected. 6. A light source comprising a laser diode module according to claim 5, wherein the heat pipe is a round heat pipe, and a heat radiating fin is provided on a heat radiating portion of the round heat pipe.