JPH02281781A - Semiconductor laser array device - Google Patents

Abstract

PURPOSE:To obtain continuous oscillation by laminating, with heat radiating plates between, plural pieces of semiconductor laser arrays, in each of which plural pieces of laser emitting points are arranged one-dimensionally, and forming fluid lines for cooling in each heat radiating plate. CONSTITUTION:Plural pieces of semiconductor arrays 1, in each of which plural pieces of laser emitting points are arranged one-dimensionally, are laminated with heat radiating plates 3 between, and fluid lines 4 for cooling are formed in each heat radiating plate 3. Furthermore, electrode terminals 6 are provided through insulating plates 5 at the top and bottom of a two-dimensional semiconductor laser array 1 wherein the semiconductor arrays 1 and the heat radiating plates 3 are piled up alternately. Hereby, the heat generated by the semiconductor array 1 can be removed enough by the fluid for cooling, and the life of the device can be prolonged, and continuous oscillation can be done with large output.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a high-output semiconductor laser array device used for excitation and processing of solid-state laser crystals.

Conventional technology semiconductor lasers have a narrow spectral width and high efficiency, and Nd
:Since efficient excitation can be achieved by matching the wavelength to the absorption spectrum of a solid-state laser crystal such as a YAG crystal, it has recently attracted attention as a solid-state laser excitation light source in place of conventional lamps. When a semiconductor laser is used as an excitation light source for a fixed laser, it is necessary that the excitation light source has a high optical density. The size of the emission area of a semiconductor laser is 1
Since it is approximately 0 μm x 2 μm, it is possible to obtain extremely high light density by creating a semiconductor laser array in which a large number of laser light emission points, which are light emitting parts, are arranged one-dimensionally (linearly) or two-dimensionally (planarly). It is. The overall efficiency when a semiconductor laser is used as the excitation light source of a YAG laser is:
Since the electrical-to-optical conversion efficiency of a semiconductor laser is 30% and the input pumping light to laser output light conversion efficiency of a YAG laser is 30%, a value close to 10% can be obtained, which is more than 10 times that of lamp pumping. Become. Furthermore, there is no heat generation in the crystal due to absorption of light of extra wavelengths, and cooling of the YAG laser is also reduced. Conventionally, in order to obtain high output with a semiconductor laser, it is necessary to arrange a large number of laser beam emission points with high density two-dimensionally, that is, on a plane. By the way, since a semiconductor laser uses a cleavage plane of a crystal as a resonator, it is not easy to monolithically arrange laser light emitting points on two substrates.

Therefore, it is conceivable to use a bar-shaped semiconductor laser array in which laser beam emission points are arranged in the negative dimension, and to further arrange this in two dimensions.

Problems to be Solved by the Invention When the light emitting points of semiconductor lasers are arranged in high density, heat generation becomes a problem. In particular, the threshold current value of a semiconductor laser is sensitive to temperature, and a phenomenon occurs in which optical output is saturated due to heat generation of the element. Furthermore, operation at high temperatures significantly shortens the life of the device. For example, if the element temperature increases by 10 degrees, the lifetime will be halved. Therefore, in order to increase the maximum optical output, it is important to efficiently dissipate heat and keep the element temperature low, but conventional heat dissipation using a simple block-shaped heat sink was not sufficient. Note that if heat dissipation is poor, it is very difficult to obtain continuous oscillation, and only slow pulse operation with a short pulse width (1 μs or less) and slow repetition can be performed.

Therefore, an object of the present invention is to provide a semiconductor laser array device that can solve the above problems.

Means for Resolving the Problems In order to solve the above problems, the semiconductor laser array device of the present invention includes a semiconductor laser array in which a plurality of laser beam emission points are arranged in one dimension, with a heat sink placed between them. A plurality of heat dissipating plates are stacked together, and cooling driftwood pipes are formed on each of these heat sinks.

Operation In the above configuration, the heat generated in the semiconductor laser array is forcibly and sufficiently removed by the cooling fluid flowing in the pipes of each heat sink, and the heat is sufficiently radiated. Therefore, temperature rise in the semiconductor laser array is suppressed and continuous oscillation is also possible.

solid line example Hereinafter, one embodiment of the present invention will be described based on the drawings.

FIG. 1 shows an external perspective view of a semiconductor laser array device, and FIG. 2 shows a perspective view of the main parts of the device.

In FIGS. 1 and 2, reference numeral 1 denotes a bar-shaped semiconductor laser array, which is composed of, for example, 10 laser beam emission points (also referred to as light emitting points) arranged one-dimensionally at intervals of 100 μm. The diameter is 1.2 mm, the thickness is 100 μm, and the resonator length is 250 μm.

Then, this semiconductor laser array 1, five insulating spacers 2 each having the same thickness as the semiconductor laser array 1, and heat sinks 3 are alternately laminated to obtain a two-dimensional array of laser beam emission points. The insulating spacers 2 are arranged on three sides of the semiconductor laser array 1 except for the laser beam emission point. Further, for the heat dissipation plate 3, diamond is the best in terms of thermal conductivity, but copper is used in terms of cost and ease of processing. The thickness of this heat sink 3 is 1
Nine holes 4 (an example of a conduit, which may be formed by inserting a pipe, for example) with a diameter of 80 μm are formed at intervals of 100 μm to allow a cooling fluid such as fluorocarbon gas to flow inside. Further, the surface of the heat dissipation plate 3 is metallized with gold, and is fused to the semiconductor laser array 1 using a solder material such as gold-tin or lead-pot. In addition,
Since the solder material has poor thermal conductivity, its thickness is kept as thin as 3 μm. Further, electrode terminals 6 are provided on the upper and lower surfaces of the two-dimensional semiconductor laser array 1 in which semiconductor laser arrays 1 and heat sinks 3 are alternately stacked, with insulating plates 5 interposed therebetween. The electrode terminal 6 and the heat sink 3 are connected by gold wires 7, and the number of gold wires 7 is about 50 in order to pass a large current of nearly 10A.

In the above configuration, the fluorocarbon gas A is caused to flow into each hole 4 of the heat sink 3 at a predetermined flow rate, and the heat generated in each semiconductor laser array 1 is forcibly removed, so that sufficient heat radiation is achieved. Note that in FIGS. 1 and 2, arrow B indicates laser light emitted from the semiconductor laser array 1.

Here, the current-output characteristics of the above semiconductor laser array 1 are shown in FIG. 3. Since five semiconductor laser arrays 1 are connected in series, the applied voltage is approximately 1 (IV
becomes. As you can see from Figure 3, 20W at 6A current
The above optical output has been obtained, and the conversion efficiency from electricity to laser light is 33%, which is a very good result.The area of the laser light emission point, which is the light emitting part, is approximately 1 city 2. The optical density was 2 kW/aa, and satisfactory characteristics were obtained as a pumping light source for a YAG laser. Note that, in order to increase heat dissipation efficiency, it is desirable that each insulating spacer 2 also have holes for flowing cooling fluid.

In addition to #1 (Cu) and diamond (C), for example, boron nitride (BN), silicon carbide (SiC), beryllia (Bed), aluminum nitride (AI2N), etc. are used as the material for the heat sink 3. Ru.

Effects of the Invention As described above, according to the configuration of the present invention, cooling fluid conduits are formed in each of the heat sinks stacked alternately with the semiconductor laser array arranged in the − dimension. The cooling fluid can sufficiently remove the heat generated by the device, thereby extending the life of the device and allowing continuous oscillation with a large output. especially,
This semiconductor laser array device is suitable as a continuous operation excitation light source for slab-type solid-state lasers, and by integrating a large number of semiconductor laser arrays, it is possible to realize a highly efficient KW-class continuous wave slab-type solid-state laser. It is something.

[Brief explanation of drawings]

FIG. 1 is an external perspective view of an embodiment of the semiconductor laser array device of the present invention, FIG. 2 is a sectional view of essential parts of the semiconductor laser array device, and FIG. 3 is current-light output characteristics of the semiconductor laser array device. It is a diagram. 1... Semiconductor laser array, 2... Insulating spacer,
3... Heat sink, 4... Hole, 5... Insulating plate. Agent Yoshihiro Morimoto J Roku Noko (W)

Claims (1)

[Claims] 1. A semiconductor laser in which a plurality of semiconductor laser arrays each having a plurality of laser beam emission points arranged one-dimensionally are stacked with a heat sink in between, and a cooling fluid conduit is formed in each of these heat sinks. Array device.