JPH05167143A - Semiconductor laser equipment - Google Patents

Abstract

PURPOSE:To provide a semiconductor laser equipment in which a cooler attached to a light emitting unit thereof can be reduced in size by a safe and simple method and a plurality of light emitting units thereof can be disposed near at hand. CONSTITUTION:An array semiconductor laser 1 having an optical output 10W is used as a semiconductor laser, mounted at a temperature control Peltier element 3 for controlling a temperature of the laser 1 through a copper spacer 2, integrally disposed on a copper heat block 4, the block 4 is fixed to one side end of a heat pipe 5, a radiating fin 6 is mounted at the other, and forcibly air-cooled by an air cooling fan 7, thereby obtaining an excellent operation of the laser 1. After emitted lights from the two lasers 1 disposed near a light emitting unit 8 are collimated by a collimator lens 9, and polarized planes are disposed to match the input port of a polarized wave combining polarizing beam splitter 10 to obtain a polarized wave combining optical output 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an application field in which a semiconductor laser is used as a light energy source (for example, solid-state laser pumping and laser microprocessing).

[0002]

2. Description of the Related Art A semiconductor laser for injecting a current into a narrow active layer has a very high optical / electrical conversion efficiency, some of which exceed 50%. However, the remaining 50% is changed to heat, and it is understood that this is extremely large from the viewpoint of local heat generation. Taking a high-power type semiconductor laser that has made remarkable progress in recent years as an example, the active layer width 20
A semiconductor laser having 0 μm, a length of 300 μm, an optical output of 1 W, and an optical / electrical conversion efficiency of 30% has a power of 3.9 kW / cm ² . This leads to destruction by melting of the semiconductor unless some forced cooling is done. For this reason, electronic cooling and air cooling by Peltier elements are widely performed (see, for example, 1991 PRODUCT CATALOG p56: SPECTRA DIODE LABS).

[0003]

However, in the conventional semiconductor laser device, the heat radiating portion such as the heat sink is integrated with the light emitting portion of the semiconductor laser, so that the volume occupied by the light emitting portion of one semiconductor laser is small. It is difficult to arrange the light emitting portions of a plurality of semiconductor lasers close to each other and to integrate the powers of the plurality of semiconductor lasers as one optical energy source by a technique such as polarization combination. In this case, originally, the characteristics of the semiconductor laser which is small in size, high in efficiency and high in output cannot be fully utilized. On the other hand, water cooling can solve the above-mentioned problem in that heat generated from the semiconductor laser is once moved through water and finally dissipated by a radiator installed in another place. If water leaks from the semiconductor laser side, it is fatal. Further, since the piping and the circulation pump are required, the whole apparatus becomes complicated and inevitably becomes large.

The present invention has been made in view of the above circumstances, and downsizes a cooling unit associated with a light emitting unit of a semiconductor laser by a safe and simple method, and arranges a plurality of light emitting units of semiconductor lasers close to each other. It is an object of the present invention to provide a semiconductor laser device that can be manufactured.

[0005]

To achieve the above object, as means of the present invention, in a semiconductor laser device, heat generation from a semiconductor laser or heat generation from an electronic cooling element for controlling the temperature of the semiconductor laser is performed. It is equipped with a heat pipe for removal.

[0006]

In the present invention, the heat generated from the semiconductor laser or the electronic cooling element for controlling the temperature of the semiconductor laser is removed by the heat pipe. The heat pipe is a hollow pipe made of a metal having a good thermal conductivity such as copper, in which water or chlorofluorocarbon vapor is sealed at low pressure. When a heating element is attached to one end of the heat pipe and a radiator such as fins is attached to the other end, the steam heated on the heating element side moves to the radiator side at high speed, and the heat is taken away by the radiator to become liquid. Become. If this liquid is returned to the heating element side by the inclination of the heat pipe or the like, this cycle is repeated. Thus, heat is transferred from the heating element to the radiator via the steam.

Since the heat pipe has a cylindrical shape, it is necessary to transmit heat to the heat pipe through a heat block for attaching the semiconductor laser package or the electronic cooling element, which is a heat source, to the heat pipe. The heat block is made of copper or the like having good thermal conductivity. The shape on one side is processed according to the shape of the semiconductor laser package or the electronic cooling element, and the other side is hollowed out according to the shape of the heat pipe. When combining these, the gap is filled with a filler having good thermal conductivity such as silicon grease or silver paste. At the other end of the heat pipe, a fin for radiating heat, a fan for forcibly cooling the fin, or a water cooler, etc. are attached in some cases.
In this way, the cooling section associated with the light emitting section of the semiconductor laser can be substantially downsized.

[0008]

EXAMPLES In order to further clarify the features and advantages of the present invention, detailed description will be given below based on examples.

FIG. 1 shows an embodiment in which two semiconductor laser devices for removing heat generated from a semiconductor laser and an electronic cooling element for controlling the temperature of the semiconductor laser by using a heat pipe are used to perform polarization combination. It is a schematic diagram. As shown in FIG. 1, as a semiconductor laser, one active layer has a width of 100 μm.
An array semiconductor laser 1 with an optical output of 10 W, in which 20 pieces each having a length of m and a length of 250 μm are arranged one-dimensionally, is used to control the temperature of the semiconductor laser through a copper spacer 2 for fixing the array semiconductor laser 1. It was attached to a Peltier element 3 used as a cooling element. These were integrated and attached to a copper heat block 4, and the heat block 4 was fixed to one end of a heat pipe 5. As the heat pipe 5, a copper pipe having a diameter of 16 mm and a length of 250 mm was used. This is selected from the viewpoint of a heat pipe that is as small as possible, capable of removing the heat quantity of the heat quantity of one semiconductor laser and the heat quantity of the Peltier element for controlling the temperature of the semiconductor laser. The dimensions do not have to be the above as long as they satisfy the above conditions. The interface between the individual objects was coated with thermally conductive silicone grease. A fin 6 for radiating heat was attached to the other end of the heat pipe 5, and forced air cooling was performed by an air cooling fan 7. The heat generated from the array semiconductor laser 1 and the heat generated from the Peltier element 3 for controlling the temperature of the array semiconductor laser 1 are satisfactorily transferred to the heat radiation fins 6 via the heat pipe 5, and the array semiconductor laser 1
Worked well. The size including the heat block 4 is substantially sufficiently compact with respect to the light emitting section 8 of the array semiconductor laser 1, and only two units as shown in FIG. 1 are provided with such a compact cooling section. It has become possible to arrange the light emitting portions 8 of the array semiconductor laser 1 close to each other.
That is, after the two array semiconductor lasers 1 are collimated by the collimating lens 9, each polarization plane is used for polarization combination.
It was arranged so as to fit one of the two 0 input ports.
As a result, the laser beams emitted from the two 10 W type array semiconductor lasers 1 were perfectly coaxially aligned, and 18 W was obtained as the combined optical output 11. A strong photoelectric field can be obtained by further condensing this with a condensing lens. Moreover, if the wavelength of the semiconductor laser is changed and a dichroic mirror is used, the optical power can be integrated with even higher density.

In the embodiment of the present invention, the Peltier element is used for controlling the temperature of the LD. However, when the temperature control is not necessary, the LD may be directly attached to the heat block. Further, although the spacer and the heat block are made of copper, they may be made of other material having good thermal conductivity.

[0011]

In the semiconductor laser device having such a structure as the cooling mechanism, the cooling section associated with the light emitting section of the semiconductor laser can be downsized, and the light emitting sections of a plurality of semiconductor lasers can be arranged close to each other. The use of semiconductor lasers as power lasers is promoted in various industrial fields such as heavy industry, semiconductor industry, and medical care.

[Brief description of drawings]

FIG. 1 is a schematic diagram of an embodiment in which polarization synthesizing is performed using two semiconductor laser devices that remove heat generated from a semiconductor laser and an electronic cooling element for controlling the temperature of the semiconductor laser by using a heat pipe. is there.

[Explanation of symbols]

 1 Array Semiconductor Laser 2 Copper Spacer 3 Peltier Element 4 Heat Block 5 Heat Pipe 6 Heat Fin 7 Air Cooling Fan 8 Array Semiconductor Laser Light Emitting Section 9 Collimating Lens 10 Polarizing Beam Splitter 11 Composite Light Output

Claims (1)

[Claims] 1. A semiconductor laser device comprising a heat pipe for removing heat generated from the semiconductor laser or heat generated from an electronic cooling element for controlling the temperature of the semiconductor laser.