JPH06164030A - Laser oscillation apparatus - Google Patents

Abstract

PURPOSE:To enhance the performance of an apparatus by a method wherein a shielding plate as a mode selector restrains that a temperature rises due to irradiation with a laser beam, the damage of the shielding plate itself is prevented and the dew condensation of an optical instrument in the circumference is prevented. CONSTITUTION:A shielding plate 11 and a holder 15 for protection use are indicated. The holder 15 is composed of a case 16 and a cover 17. The shielding plate 11 is composed of a ceramic whose main crystal phase is fluorine mica, and it is provided with a hole in a very small diameter in order to limit the luminous-flux diameter of a laser beam. The reflection factor of the ceramic with reference to the laser beam is high, and the ceramic is provided with a highly heat-resistant property. When the laser beam is passed through the hole, the circumference of the hole in the shielding plate 11 is irradiated with one part of the beam, but the beam is reflected here sufficiently, the laser beam penetrates well through the shielding plate 11 and the laser beam which is absorbed here is reduced. Since the shielding plate is durable against heating due to the reduced laser beam, it is possible to achieve its aim.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shield plate as a mode selector, which is installed at an intermediate position between a pair of reflecting mirrors and has an opening for limiting the beam diameter of laser light.
The present invention relates to a laser oscillating device improved so as to prevent damage to itself and prevent dew condensation of peripheral optical devices by suppressing a temperature rise due to laser light irradiation.

[0002]

2. Description of the Related Art FIG. 4 is a perspective view common to a conventional example and each embodiment according to the invention to be described later. In the figure, a total reflection mirror 1 and an output mirror 2 are coaxially opposed to each other, and Y is provided in the middle thereof.
An AG storage unit 3, an ultrasonic Q switch 7, a shield plate 8 as a mode selector, and a shutter 9 are arranged. In the YAG storage unit 3 indicated by a chain double-dashed line, an elliptic cylindrical condenser 6 whose inner surface is a reflecting mirror, a YAG rod 4 positioned with its axis aligned with each focus position, and a continuous excitation lamp A krypton arc lamp (hereinafter simply called a lamp)
5 and 5 are stored and installed respectively. The axis of the YAG rod 4 is the optical axis of this device.

The ultrasonic Q switch 7 is a kind of on / off type switch utilizing ultrasonic waves, and has a high peak value for the excitation energy accumulated in the inverted distribution state inside the YAG rod 4 optically excited by the lamp 5. And repetitively pulsed laser light having a narrow time width. The shield plate 8 as a mode selector is a shield plate having micro holes (micro openings) for selecting a lateral mode suitable for laser light processing. The micro holes change the beam diameter of the laser light. Limits and suppresses oscillation of unnecessary modes around. In the conventional example, the shielding plate 8 is made of stainless steel, is housed in a protection holder (not shown), and has an optical axis adjusting means. The shutter 9 is a safety device that performs an emergency cutoff of laser oscillation, and does not normally turn on / off the laser light.

[0004]

In the conventional example, since the shielding plate 8 as the mode selector is made of stainless steel, it is heated by irradiating the peripheral portion of the minute hole with laser light, and the temperature rises. Due to this temperature rise, the shielding plate 8
There is a risk that the device itself or a holder holding the device may be damaged or that dew may condense on the peripheral optical equipment, and the performance of the device may be degraded or stopped.

An object of the present invention is to solve the above problems of the prior art and to suppress the temperature rise of the shield plate as a mode selector due to the irradiation of laser light.
It is an object of the present invention to provide a laser oscillating device improved so as to prevent damage to itself and to prevent dew condensation on peripheral optical devices.

[0006]

According to a first aspect of the present invention, there is provided a laser oscillating device having an opening for limiting the diameter of a laser beam, which is formed at an intermediate position between a pair of reflecting mirrors arranged on opposite sides of a laser medium. In a device provided with a shield plate as a mode selector, the shield plate is made of ceramics having a high reflectance for laser light and high heat resistance.

According to another aspect of the laser oscillating device, an opening for limiting the beam diameter of the laser light is provided at an intermediate position between a pair of reflecting mirrors which are arranged to face each other on both sides of the laser medium.
In a device in which a shield plate is installed as a mode selector, the shield plate is made of a glass material having a high laser light transmittance, at least one surface of which has a diffuse reflection treatment at least around the opening.

According to a third aspect of the present invention, there is provided a laser oscillating device, which has an opening at a middle position between a pair of reflecting mirrors arranged on opposite sides of a laser medium so as to limit a beam diameter of a laser beam.
In a device in which a shield plate is installed as a mode selector, the shield plate has a high laser light transmittance, at least on one surface of which at least an opening peripheral portion is subjected to a coating treatment for reflection of laser light. Made of glass material.

[0009]

In the laser oscillating device according to the first aspect of the present invention, since the shield plate is made of ceramics having a high reflectance for the laser light and high heat resistance, the laser light that passes through the shield plate well and is absorbed there. In addition to being reduced, it has durability against heating by laser light.

In the laser oscillating device according to the second aspect of the present invention, since the shield plate is made of a glass material having a high transmittance of laser light, at least the periphery of the opening of at least one surface of the shield plate is subjected to the diffuse reflection treatment. Is diffused and reflected by the periphery of the opening of the shielding plate, and passes through the shielding plate well, so that the heating effect of the laser light on the shielding plate is reduced, and due to the diffuse reflection, the reflected light is reflected on a specific part of the peripheral portion. Irradiate strongly and avoid heating here.

In the laser oscillator according to the third aspect of the present invention, the shielding plate is a glass material in which at least one peripheral surface of at least one side of the shield plate is subjected to antireflection coating treatment for laser light and has high laser light transmittance. Therefore, the laser light is suppressed from being reflected at the peripheral portion of the opening of the shield plate, the reflected light irradiates the peripheral portion, and it is possible to avoid heating here, and since it is well transmitted through the shield plate,
The heating effect of the laser light on the shield plate is reduced.

[0012]

Embodiments of the laser oscillator according to the present invention will be described below with reference to the drawings. FIG. 4 is a perspective view common to each embodiment and the conventional example, which has already been described in the conventional example. The difference between each embodiment and the conventional example lies in the shielding plate. Therefore, of the other members, the same members as those in the conventional example are designated by the same reference numerals, and the description thereof will be omitted.

FIG. 1 is a sectional view of the essential parts of the first embodiment.
In FIG. 1, a shield plate 11 and a holder 15 that is stored to protect the shield plate 11 are shown. The holder 15 is a case 16
And a cover 17. Now, the shielding plate 11 is a disk-shaped component made of ceramics whose main crystal phase is fluoromica, and has a hole having a minute diameter for limiting the diameter of the light beam of the laser beam in the central portion. This ceramic has high reflectance to laser light and high heat resistance. Therefore, when the laser light passes through the hole, a part of the light irradiates the peripheral portion of the hole of the shield plate 11, but it is sufficiently reflected here and passes through the shield plate 11 well. The absorbed laser light is reduced. Moreover, it has durability against heating by the reduced laser light. As a result, the temperature rise due to the irradiation of the laser beam is suppressed, and the high heat resistance prevents the shield plate itself from being damaged.

FIG. 2 is a sectional view of the shield plate of the second embodiment. In FIG. 2, the shielding plate 12 has the same shape and dimensions as those of the first embodiment, but is made of a glass material having a high laser beam transmittance, and has a diffuse reflection process as shown by a broken line on one side, That is, a forming process of fine irregularities is performed. Here, the diffuse reflection process is better if it is on both sides,
Further, it does not have to be the entire side surface, but at least the peripheral portion of the hole. Therefore, the laser light is diffusely reflected at least at the peripheral portion of the hole of the shield plate 12, and at the same time, the shield plate 12
Since the laser beam is transmitted through well, the heating effect of the laser beam on the shielding plate 12 is reduced, and due to diffuse reflection, the reflected light strongly irradiates a specific portion of the peripheral portion and heats it. Can be avoided.

FIG. 3 is a sectional view of the shield plate of the third embodiment. In FIG. 3, the shielding plate 13 has the same shape and dimensions as those of the first embodiment, but is made of a glass material having a high laser light transmittance, and has an antireflection coating on one side surface as shown by a solid line. Is applied. Here, as in the second embodiment, the antireflection coating is better on both side surfaces, and not only the entire side surfaces, but at least the peripheral portion of the hole. Therefore, the laser light is suppressed from being reflected at least in the peripheral portion of the hole of the shield plate 13, the reflected light does not irradiate the peripheral portion, and accordingly, the peripheral portion is heated, and the diamond can be condensed. can avoid. Moreover, since the transmittance of the laser light to the shield plate 13 is good, the heating action is reduced.

[0016]

(1) In the laser oscillating device according to the first aspect of the present invention, the laser light which is transmitted through the shield plate and absorbed therein is reduced, and the shield plate is also protected against heating by the reduced laser light. (2) In the laser oscillating device according to claim 2, since the laser light is diffused and reflected at the peripheral portion of the opening of the shield plate and well passes through the shield plate, the heating action of the laser light on the shield plate is achieved. In addition, the reflected light strongly irradiates a specific portion of the peripheral portion and does not heat the diffused reflection due to the diffuse reflection, and the laser light is shielded by the laser oscillation device according to claim (3). The reflection around the opening of the plate is suppressed, the reflected light irradiates the periphery,
It is possible to avoid heating here, and since it passes through the shielding plate well, the heating effect of the laser beam on the shielding plate is reduced.

Therefore, in common with each claim, by suppressing the temperature rise due to the irradiation of the laser light, the shield plate itself is prevented from being damaged, the heating of the peripheral optical equipment by the reflected laser light is suppressed, and the dew condensation is caused. Prevented, and as a result,
The laser oscillation function is fully exerted, the means is simple, and there is no change in the shape or size of the shield plate itself, so the cost increase is small and the implementation is easy. ─ has the effect.

[Brief description of drawings]

FIG. 1 is a sectional view of an essential part of a first embodiment according to the present invention.

FIG. 2 is a sectional view of a shielding plate according to a second embodiment.

FIG. 3 is a sectional view of a shielding plate according to a third embodiment.

FIG. 4 is a perspective view common to each embodiment and the conventional example.

[Explanation of symbols]

 1 Total Reflector 2 Output Mirror 3 YAG Storage 4 YAG Rod 5 Lamp 6 Concentrator 7 Ultrasonic Q Switch 8 Shielding Plate 9 Shutters 11, 12, 13 Shielding Plate 15 Holder 16 Case 17 Cover

Claims (3)

[Claims] 1. A device in which a shielding plate having an opening for limiting a light beam diameter of a laser beam is installed at an intermediate position of a pair of reflecting mirrors arranged so as to face each other on both sides of a laser medium. A laser oscillating device, which is made of ceramics having high reflectance for laser light and high heat resistance. 2. A device in which a shield plate having an opening for limiting a light beam diameter of a laser beam is installed at an intermediate position of a pair of reflecting mirrors arranged to face each other on both sides of a laser medium. A laser oscillating device, characterized in that at least one surface of at least one side thereof is subjected to a diffuse reflection treatment, and is made of a glass material having a high laser light transmittance. 3. A device in which a shield plate having an opening for limiting a light beam diameter of a laser beam is installed at an intermediate position of a pair of reflection mirrors arranged to face each other on both sides of a laser medium. A laser oscillating device, characterized in that at least a peripheral portion of the surface of at least one side is coated with a coating for preventing reflection of laser light, and is made of a glass material having a high transmittance of laser light.