JPH0624276B2 - Laser device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser device, and more particularly to a laser device suitable for transmitting laser light between a plurality of reflecting mirrors.

[Background of the Invention]

Generally, a laser generator emits a laser beam by performing glow discharge in a resonator having a mirror to excite a gas medium such as carbon dioxide gas, helium gas or nitrogen gas. The laser light resonates between a plurality of reflection mirrors in the resonator, amplifies the laser light, and is radiated to the outside from one of the semitransparent mirrors, which is ZnSe, for example. If the workpiece is irradiated with the laser light, the workpiece can be subjected to processing such as cutting, welding, and surface treatment. The processing time of the workpiece can be processed faster as the energy density of the laser light is higher. In order to increase the energy density of the laser light, the resonance distance may be lengthened to increase the excitation space between the reflection mirrors to amplify the laser light, or the reflectance of the reflection mirror may be improved.

Traditionally, reflection mirrors have been manufactured using oxygen-free copper, beryllium copper,
The member to be polished such as aluminum has been processed by the lapping method. The lapping method is a method in which a polishing dish is brought into contact with a member to be polished fixed to a rotary table, one side of the member to be polished is swung by the polishing dish while the rotary table is rotated, and an abrasive is contained between them. A liquid is appropriately dropped to form a reflection mirror on one surface of the member to be polished. By the time the reflective mirror is formed, the polishing dish, the liquid is rough, medium and
Replace according to the finishing lap. Therefore, a lot of work time and skill are required.

Therefore, if the member to be processed is processed by the diamond cutting method by ultra-precision processing to form the reflection mirror, the working time can be greatly shortened and less skill is required. However, when the reflecting surface of the cutting reflecting mirror is observed microscopically, the cutting reflecting mirror has a sawtooth wave shape in cross section, and the sawtooth wave shape forms an inclined surface. For this reason, if the reflecting mirrors are simply combined, the incident angle of the incident light and the reflected light of the laser light on each inclined surface becomes large, and the laser light often radiates to other than between the reflecting mirrors. Alternatively, laser light is emitted between the reflection mirrors in a specific direction, the resonance distance is not uniform, and the energy density characteristic of the laser light output becomes unstable. There is a problem in that the work cannot be neatly processed when the work is processed with a laser beam having an unstable energy density characteristic, for example, a recess is formed.

[Object of the Invention]

An object of the present invention is to provide a laser device which can make laser light uniform between reflection mirrors, keep the energy density of laser light output stable, and perform processing neatly.

[Outline of Invention]

In order to achieve this object, the laser device of the present invention, a pair of reflection mirrors having a sawtooth wave-shaped inclined surface of a certain direction formed on the surface of the reflection surface are arranged to face each other, one inclined surface and the other inclined surface. It is characterized in that they are arranged so as to be orthogonal to each other.

Example of Invention

An embodiment of the present invention will be described below with reference to the orthogonal gas laser generator shown in FIG.

As shown in the figure, the mixed gas 1 is usually an anode 2 and a cathode 3.
And a voltage is applied to both electrodes to generate a Gello discharge, an excitation space 4 is formed. An output mirror 5 and a total reflection mirror 6 and first and second folding mirrors 7 and 8 which are plane mirrors are arranged corresponding to the excitation space, and a laser beam 9 resonates between these mirrors. There are five optical axes 9A to 9E of the laser light 9 in the excitation space. Each mirror is constructed as shown in FIG.

The resonator body 10 has end plates 13 and 14 mounted in a direction perpendicular to the gas flow port 11 shown on the side surface via a bellows 12. An output mirror 5 and a total reflection mirror 6 are attached to the outer surfaces of the end plates 13 and 14 via bellows 15. First and second folding mirrors 7 and 8 are attached to the inner surface of each of the end plates 13 and 14 adjacent to the output mirror 5 and the total reflection mirror 6 via a mount 16. First
The folding mirror 7 and the second folding mirror 8 are reflective surfaces 2 with respect to each other.
0 and 21 are attached to the mounting base 16 so as to correspond in an inclined state.

The reflecting surfaces 20 and 21 are, as shown in FIGS. 3 (A), (B) and (C),
It has a sawtooth cross section. One reflecting surface 20 forms a plurality of inclined surfaces 22 in the horizontal direction. The other reflecting surface 21 forms a plurality of inclined surfaces 23 in the vertical direction orthogonal to the one reflecting surface 20. The height dimension H of the inclined surfaces 22 and 23 is formed such that the height dimension is gradually reduced from the inclined surface convex portion 24 having a sawtooth-shaped cross section to the concave portion 25. The direction in which the horizontal inclined surface 22 and the vertical inclined surface 23 are orthogonal to each other irradiates the reflecting surface with laser light from a He-Ne laser, projects the reflected light on a screen, and projects the projected light toward the projected portion. Marks 26 and 27 are attached to make them orthogonal. (The mark may be attached to the back surface of the reflection mirror.) With this configuration, the incident light 9A of the laser light 9 enters the vertically inclined surface 23, and again becomes the reflected light 9B from the reflecting surface 21 and is horizontal. The light enters the inclined surface 22 in the direction as incoming light.
At this time, the angle formed by the incident light 9A and the reflected light 9B is referred to as a reflection angle n. Therefore, the reflected light 9 from the one inclined surface 23
B advances to the other inclined surface 22 substantially in parallel, and thereafter the inclination angle θ
The laser beam 9 is pumped and amplified while resonating from the upper right side to the lower left side in the figure as it is accumulated in the reflection angle n as much as n ₁ n ₂ n ₃ ... After being mixed uniformly, the energy density characteristic A of the laser light output becomes stable as shown in FIGS. 4 (A) and 4 (B).

In FIG. 4 (A), the vertical axis represents the energy density (E), the horizontal axis represents the diameter 1 of the laser beam 9, and the left and right circumferential ends ½l from the center O of the diameter 1 are shown. The energy density characteristic A is the present invention, while the energy density characteristic B is shown in FIG.
This is a case where the inclined surfaces 22 and 23 of (A) and (B) are arranged in the same direction, for example, horizontally or vertically. As is clear from this characteristic diagram, the energy density characteristic A is more stable than the energy density characteristic B with a constant waveform. Microscopically observing these energy density characteristics A and B, the amplitude 8A of the energy density characteristic A is smaller than the amplitude 8B of the energy density characteristic B as shown in FIG.

Observing the burn pattern (burn mark) generated when the laser beam 9 having the energy density characteristics A and B is applied to the work piece, for example, the acrylic plate 30, the burn pattern A ′ of the present invention is uneven as shown in FIG. Although it is difficult to form a portion, in the burn mark B ′ of the energy density characteristic B, an uneven portion is formed as shown by a chain line. Therefore, if the laser device of the present invention is used for processing, such as drilling and cutting, it can be completed neatly.

〔The invention's effect〕

As described above, according to the laser device of the present invention, the energy density of the laser light output can be stabilized, so that there is an effect that processing can be performed neatly.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic explanatory view of an orthogonal gas laser generator shown as an embodiment of the present invention, FIG. 2 is an explanatory view near a resonator of FIG. 1, and FIG. 3 is a folding mirror. In the figure (A),
(B) is a perspective view, (C) is a schematic side sectional view, (A) is an energy density characteristic diagram of laser light output, and (B) is (A).
FIG. 3C is a burn pattern diagram of an acrylic plate. 7, 8 ... Folding mirror, 9 ... Laser light, 20, 21 ...
… Reflective surfaces, 22, 23 …… Inclined surfaces.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Fumio Shibata 4-6 Kanda Surugadai, Chiyoda-ku, Tokyo Inside Hitachi, Ltd. (72) Inventor Isao Mori 1-1-1 Kokubuncho, Hitachi City, Ibaraki Stock Company Hitachi Kokubu Factory

Claims (1)

[Claims] 1. A laser device in which laser light is transmitted between a plurality of reflecting mirrors, wherein, of the plurality of reflecting mirrors, a pair of reflecting mirrors facing each other has a reflecting surface having a sawtooth-shaped inclination in a certain direction. A laser device in which a surface is formed, and the one inclined surface and the other inclined surface of a pair of mirrors facing each other are arranged so as to be orthogonal to each other.