JPS61204990A - Solid state laser oscillator - Google Patents

Abstract

PURPOSE:To prevent unstable emission of a laser beam, by providing transparent plates on the exciting surfaces of a laser material so as to contact it, cooling the material through the transparent plates, thereby keeping the laser material optically stable during oscillation. CONSTITUTION:Cooling water is introduced from a cooling-medium feeding path 16, and a laser material 4 and the like are cooled. Exciting lamps 5 and 6 are lighted. The light is projected on the laser material 4 through transparent plates 14 and 15. The light is totally reflected within the laser material 4 and resonated. Thus laser oscillation is generated. The laser material 4 is heated and temperature is increased. At this time, temperature distribution is yielded by the amount of heating and heat radiation to the surrounding part. When the heat conductivity of the material of the transparent plates 14 and 15 is equal to or less than that of the laser material 4 and when the contacting degree of the transparent plates 4 and 5 with the exciting surfaces at both sides of the laser material 4 is high, the temperature distribution at the exciting surfaces become uniform. The temperature of the transparent plates 14 and 15 is cooled to about the temperature of the cooling water. Even if the cooling water does not flow uniformly and irregular cooling occurs, the effect of it is not received since the thickness of the plate acts as buffer.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a solid-state laser oscillation device including a flat plate or columnar laser material having a rectangular cross section.

In particular, the present invention relates to a device that can keep a laser substance optically stable during oscillation.

[Technical background of the invention]

The oscillation device equipped with the above-mentioned fine laser material is known as a so-called slab type laser oscillation device. This device uses a laser device that uniformly optically excites the laser medium, and also uniformly cools the optical excitation surface, and provides thermal insulation on both sides that are perpendicular to the optical excitation surface and do not face the optical resonator. By that.

It is necessary to limit the temperature distribution within the laser medium to only one direction. For uniform excitation, a large number of books are bent in a meandering or zigzag pattern to excite the books evenly. on the other hand.

For uniform cooling, the temperature gradient in the width direction can be reduced by flowing cooling water along the width direction perpendicular to the operator's direction of the laser medium. Alternatively, a pair of transparent plates are placed close to the excitation surface of the laser substance, and a narrow space in the close portion is used as a cooling channel for cooling.

[Problems with background technology]

In the above cooling, the cooling medium such as 2 water comes into direct contact with the material, so the temperature distribution of the cooling gravel and the difference in flow velocity (C,!:,,:) affect the cooling surface of the laser medium. A temperature gradient occurs and the optical reflection surface of the laser material is deformed, resulting in optical reflection of 5 high sugar content? f- It becomes impossible to realize.

As a result, the polarization of the laser oscillation beam is disturbed and the oscillation mode becomes higher order.

In addition, because it is structurally complex, maintenance and inspections are troublesome.7'C.

[Purpose of the invention]

An object of the present invention is to provide an entire laser f oscillation device in which a laser substance can be kept optically stable during oscillation, and an unstable laser beam can be prevented from being emitted.

L'Summary of the Invention] In a solid l/- laser generator and apparatus equipped with a v-ther substance having a rectangular cross section, a transparent plate is provided in contact with the excitation surface of the laser substance, and cooling and cooling are carried out through the transparent plate. It is configured to be cooled.

[Embodiments of the invention]

DESCRIPTION OF THE PREFERRED EMBODIMENTS All embodiments of the present invention will be disclosed and explained below with reference to the drawings.

Figure 1 L〆 Here, (1) is a frame made of an insulating material, consisting of a main body and a body that is watertightly attached to the main body.
It is composed of a divided body, and a storage section (2) is formed inside. This storage part (2) is provided with a double cylindrical condensing reflector (3) whose inner surface is a highly reflective surface. Roughly,
Inside this condensing reflector (3), there is a laser material (4) located in the middle part of the mirror, and a pair of excitation lamps (5) 9 (6) located between this L laser material (4). is provided. These laser materials (4) and an excited 11-bow lamp (5),
(6) It extends parallel to the axis of the converging reflector (3). The laser substance (4) is a flat plate with a rectangular cross section, and is linearly held by holding tubes (81 and (9)) fixed to both ends of the body through an organic adhesive such as a silicone resin adhesive. The holding tube body (8) 19) is held by the frame body (
1) An optical resonator consisting of a total reflection mirror (11) and an output mirror (121) is installed on the outside of the frame (1), which is penetrated watertightly through a laser material (1) and an output mirror (121). ) is provided facing both end faces formed in the optical part at a predetermined angle.

In addition, a heat insulating material (13) is fixed to both sides of the laser and material (4) as shown in Fig.
), (6) are formed in the direction of total reflection, and transparent plates U and L made of quartz or the like and thinner than the thickness of the laser material (4) are attached to these surfaces. I am in contact with you.

Both surfaces of each of these transparent plates are formed into one light scattering hole i. By the way, in the frame (1) (is the storage part (2)
A cooling medium supply passage αω and a discharge passage (1η) are formed which communicate with the cooling medium supply passage αω and the exhaust passage (1η).

”-5 The thermal cooling medium supply path for the laser medium during laser oscillation according to the configuration described above (cooling water is introduced from the IQ to cool the laser material (4
) etc. while cooling the excitation lamps (5) and (6).

When the emitted light is irradiated onto the laser material (4) through the entire transparent plate 04), the laser medium (4) is excited and is totally reflected in a zigzag pattern within the medium (4). while resonating.

Laser oscillation occurs. This oscillation causes the laser medium (4) to generate heat and rise in temperature. At this time, the amount of heat generated and the heat dissipated to the surroundings create a degree distribution. This temperature distribution is caused by a flat temperature distribution within the laser material (4) as shown in Figure 3, since a heat insulating material is fixed in the X direction that intersects the excitation rungs (5) and (6). (1)) is formed, and a temperature gradient is formed between the cooling water and the cooling water at the insulating material (13). On the other hand, if we look at the temperature distribution (C) in the X direction perpendicular to the 8 X direction, we can see that the laser material (4)
The thickness of the area is relatively uniform.

Transparent plate (14), ! The temperature distribution has a steep gradient where the temperature drops sharply at 1.5. Transparent plate (
14), +, If the thermal conductivity of the material of i51 is equal to or lower than that of the laser material (4), then 1/
-The substance (4) both 4+N /A liW+ tai 1/l" +, :h Jr+ 2. O[IB t
1 μ y s w to fF i k f+Al +'
tr> If the puncture position is high, the temperature distribution on the excitation surface will be uniform. The transparent plate Q4) and (151 are cooled to near the water temperature of the cooling water. Also, suppose that the cooling water is cooled to the transparent plate U.
Even if uneven cooling occurs due to insufficiently uniform flow, the thickness of these plates exhibits a buffering effect, so it will not be affected by this. In this way, the temperature distribution of the optical total reflection surface for forming the zigzag optical path of the laser medium (4) is made uniform, and an optically flat reflection optical path is formed.゛Again. The surfaces of the transparent plates α and αω are light scattering surfaces, so the excitation light is scattered and the intensity distribution is made uniform.
The uniformity of the temperature distribution described above could be made more effective.

In addition, the light scattering surfaces of the transparent plates (14) and (1!9) are I￥f
Although an effect similar to the above embodiment can be obtained even if the wafer is not formed, if it is formed, it may be formed on both sides or only on either side as described above. In addition, if a transparent plate made of a material that mainly transmits light in a spectrum that is effective as excitation light for the laser material (4) and has a filtering effect that blocks harmful ultraviolet rays and other light is used, the above effect and other effects can be obtained. .

Improves the efficiency of laser oscillation and prevents deterioration of the laser medium.

〔Effect of the invention〕

) As detailed above, the excitation surface of the laser material is reinforced with transparent plates, and the laser material is indirectly cooled by cooling these transparent plates. The heat accumulated in the laser material is removed evenly, and the uneven cooling is not affected by the above-mentioned reinforcement effect, so the optical properties of the laser material can be kept stable even during oscillation. did it. did,
Once upon a time, it was possible to stabilize the mode, polarization, etc. of laser light output by laser oscillation.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing one embodiment of the present invention, and FIG.
The sectional view taken along the line n in FIG. 1, and FIGS. 3 and 4 are temperature distribution charts.

Claims (3)

[Claims] (1) An optical resonator is provided between an optical resonator, and both end faces facing the resonance axis are formed as parallel optical surfaces at a predetermined angle, and an oppositely facing optical resonator is provided between the optical resonator and the optical resonator, and both end faces facing the resonance axis are formed as parallel optical surfaces at a predetermined angle. A laser material having a rectangular cross section and a reflecting surface, at least a pair of excitation lamps provided at a position to irradiate excitation light onto the excitation surface of this laser material, a condensing reflector surrounding the laser material and excitation lamp, and this condensing light. In a solid-state laser oscillation device, the solid-state laser oscillation device includes a frame that houses a reflecting mirror and is provided with a cooling channel for cooling at least the laser material, and means for supplying a cooling medium to the cooling channel, wherein the laser material is heated at its excitation surface. A solid-state laser oscillation device characterized in that a transparent plate is provided in contact with the solid-state laser oscillation device, and the solid-state laser oscillation device is cooled and excited through the transparent plate. (2) The solid-state laser oscillation device according to claim 1, wherein the transparent plate has light scattering properties. (3) The solid-state laser oscillation device according to claim 1, wherein the transparent plate has a filtering effect that absorbs harmful light to the laser material.