JPH0537057A - Gas laser - Google Patents

Abstract

PURPOSE:To regulate a discharging state, to reduce restriction items in manufacture, and further to visually observe the state and an interior through a space of a microwave circuit. CONSTITUTION:A microwave passed through a waveguide 9 is condensed near two parallel wires of cylindrical rods 5 formed of conductors to generate a very strong microwave electric field. A mode of the field imparts a uniform discharge to a gas laser medium of a discharging space 13 to be suitable to excite a laser. Here, the discharge can be saved by altering a relative position of the two wires used as a microwave circuit and other microwave circuit. The discharging state and the interior can be observed from a transparent plate 7 of a side plate of a laser head 1 through a space between the two wires. A restriction in manufacture of a laser is reduced, and the interior state can be visually observed, and hence the discharging state can be easily grasped.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas laser device for exciting a laser by utilizing a microwave discharge, and more particularly to a gas laser device using two parallel lines in a microwave circuit.

[0002]

2. Description of the Related Art In a gas laser device, there is a method of exciting a gas laser medium by electric discharge in order to obtain laser oscillation. If a non-uniform discharge is generated in the space and only a part of the laser medium is in a state suitable for excitation, the expected laser output cannot be obtained or the laser output fluctuates.

As a result, in order to bring the entire laser medium into a state suitable for excitation, it is necessary to have a spatially uniform discharge.

In order to meet such a demand, a technique of discharging by microwave has been proposed. Figure 2
3 and FIG. 3 show Japanese Patent Laid-Open No. 64-69067 and Japanese Patent Laid-Open No. 64-69067.
FIG. 3 is a cross-sectional view and a schematic perspective configuration diagram showing an example of a microwave carbon dioxide gas laser device disclosed in Japanese Patent Publication No. 69083.
In the figure, 1 is a laser head portion having a microwave cavity structure of a ridge waveguide type which is a kind of microwave circuit for exciting a carbon dioxide laser medium by microwave discharge, 16 is a magnetron which is a microwave oscillator, Reference numeral 9 is a waveguide for guiding the microwave output from the magnetron 16 to the laser head portion 1, 8 is a microwave coupling window for coupling the waveguide 9 to the laser head portion 1, and 2 is an upper portion in the state where the microwave is shown. A reference numeral 15 is a mirror holder which houses a reflecting mirror for laser oscillation, and a laser beam is emitted from a window of 17. Further, 3 and 14 are ridges, 11 is a groove formed in one ridge 3, and 10 is a conductor wall forming a part of a microwave circuit. In this embodiment, the bottom wall of the groove 11 is used. There is. Reference numeral 12 is a dielectric material such as alumina, which is provided so as to face the conductor wall 10 and acts as a microwave entrance window. 13 is formed between the conductor wall 10 and the dielectric 12 by the dielectric 12 covering the groove 11.
The discharge space 4 in which the carbon dioxide gas laser medium is enclosed is a cooling water channel formed in the ridge 3 having the conductor wall 10 forming a part of the microwave circuit and the ridge 14 facing the ridge 3. 2 is a sectional view taken along the line AA of FIG.

Next, the operation will be described. The microwave generated by the magnetron 16 propagates through the waveguide 9 and the impedance is matched in the microwave coupling window 8 to be efficiently coupled to the laser head unit 1. The laser head unit 1 has a ridge waveguide type cavity structure as shown in FIG. 2, and microwaves are concentrated near the ridges 3 and 14 to generate a very strong microwave electric field. The strong microwave electromagnetic field discharges and excites the carbon dioxide laser medium enclosed in the discharge space 15. Here, the laser oscillation condition can be obtained by flowing the cooling water into the cooling water passage 4 to cool the discharge plasma and appropriately selecting the discharge condition such as the pressure of the carbon dioxide gas laser gas. Then, a laser resonator is formed by a reflecting mirror in the mirror holder 15 shown in FIG. 3 and a reflecting mirror facing it, which does not appear in the drawing, and laser oscillation light is obtained and emitted from the window 17.

At this time, as in the ridge waveguide type cavity structure of the laser head portion 1 of FIG. 2, the microwave circuit has a microwave having an electric field component perpendicular to the boundary between the dielectric 12 and the carbon dioxide gas laser medium. When forming a mode, the dielectric 12
Since the conductor wall 10 and the conductor wall 10 face each other, an electric field component perpendicular to the conductor wall 10 is also generated, and an electric field penetrating the carbon dioxide laser medium can be generated. In other words, the lines of electric force are not influenced by the carbon dioxide gas laser medium and go vertically to the conductor wall 10, so that a spatially uniform discharge can be obtained. But,
The situation of this discharge is generally not visible. Also,
In order to obtain a uniform discharge, there are many restrictions on the positions and shapes of the ridges 3, 14, the top plate 2, and the microwave coupling window 8 such as processing accuracy.

[0007]

Since the conventional carbon dioxide gas laser device is constructed as described above, the positions and shapes of the ridges 3, 14, the top plate 2, and the microwave coupling window 8 are obtained in order to obtain a uniform discharge. There are many restrictions such as processing accuracy. Further, since the discharge cannot be visually observed, there is a problem that a measuring device is required when adjusting the laser device.

The present invention has been made to solve the above problems, and has a structure of a microwave circuit for forming a microwave mode having an electric field component perpendicular to the boundary between the dielectric 12 and the carbon dioxide gas laser medium. By changing
It is an object of the present invention to obtain a gas laser device capable of visually observing a discharge state while reducing constraints on manufacturing and adjustment.

[0009]

A gas laser apparatus according to the present invention has a microwave circuit for generating a microwave electric field for discharging a gas laser medium by microwave discharge to perform laser excitation. The gas laser medium is enclosed in a space formed between a conductor wall that forms a part of the conductor and a dielectric that is provided facing the conductor wall and serves as a microwave entrance window. In a microwave circuit in which a microwave mode having an electric field component perpendicular to the boundary between a dielectric and a gas laser medium is formed by the wave circuit, two parallel lines are used in the microwave circuit.

A gas laser device according to another invention of the present invention is the above-mentioned invention, wherein the microwave circuit is provided with an observation window for observing the discharge state and the internal state.

[0011]

In the present invention, by changing the structure of the microwave circuit that uniformly discharges the gas laser medium to parallel two lines, the discharge state can be adjusted and the manufacturing restrictions are reduced.

In another invention of the present invention, the discharge state and the internal state can be visually observed through the space between the parallel two lines from the observation window.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view showing a carbon dioxide laser device according to an embodiment of the present invention. In the figure, 5 is a cylindrical rod made of a conductor, that is, a cylindrical conductor. Reference numeral 7 is a mesh made of a conductor, 6 is a transparent plate to which the mesh 7 is attached, and is made of, for example, tempered glass. Others are equivalent to those denoted by the same reference numerals in FIG. 1 is shown in FIG.
The cross section corresponding to is shown.

Next, the operation will be described. The microwave generated by the magnetron 16 propagates through the waveguide 9 and the impedance is matched in the microwave coupling window 8 to be efficiently coupled to the laser head unit 1. The laser head portion 1 has a parallel two-wire type cavity structure in which cylindrical rods 5 made of a conductor are arranged in parallel as shown in FIG.
The microwave is concentrated near the two parallel lines formed by the cylindrical rod 5 to generate a very strong microwave electric field. The microwave electric field mode generated at this time has an electric field component perpendicular to the boundary between the dielectric 12 and the carbon dioxide gas laser medium. Therefore, since the dielectric 12 and the conductor wall 10 are opposed to each other, an electric field component perpendicular to the conductor wall 10 is also provided, and an electric field penetrating the carbon dioxide gas laser medium can be formed. That is, the lines of electric force are not influenced by the carbon dioxide gas laser medium and go vertically to the conductor wall, so that a spatially uniform discharge can be obtained, and the whole carbon dioxide gas laser medium can be brought into a state suitable for laser excitation.

Here, in the present invention, since the parallel two-wire type cavity structure is used for the microwave circuit, the discharge is adjusted by changing the relative positions of the parallel two wires and other microwave circuits. can do. That is, for example, by changing the width between the two parallel lines and the distance between the two parallel lines and the dielectric 12, it is possible to change the width of the discharge and the electric field strength in the discharge space 13 while uniformizing the discharge. it can.
From this, it is possible to reduce manufacturing restrictions.

Since a parallel two-wire type cavity structure is used, a space is created between the two wires. Therefore, when the transparent plate 6 to which the mesh 7 made of a conductor is attached as shown in FIG. 1 is used as a side plate, the discharge state can be visually observed through a dielectric made of a thin plate such as alumina ceramics. That is, the transparent plate 6 and the mesh 7 constitute an observation window, and it is possible to easily grasp the discharge particularly when adjusting the laser device. Moreover, the internal state can be observed. Here, the mesh 7 functions to prevent the microwave from leaking.

By the way, in the above embodiment, the case where the present invention is applied to the carbon dioxide gas laser has been described, but it goes without saying that it can be applied to other gas lasers that can be excited by microwaves. If the cylindrical conductor 5 is made hollow and cooling water is passed through the inside, the cooling effect is improved.

[0018]

As described above, according to the present invention, since the microwave circuit has the parallel two-wire type cavity structure, the discharge inside the discharge space can be made uniform, and the laser device can be manufactured. It is possible to reduce the restriction of.

As described above, according to another aspect of the present invention, since the microwave circuit is provided with the transparent observation window, the internal state can be visually observed through the space between the two parallel lines.
Moreover, the discharge state can be easily grasped.

[Brief description of drawings]

FIG. 1 is a sectional view of an embodiment of a gas laser device according to the present invention.

FIG. 2 is a sectional view showing a conventional carbon dioxide laser device.

FIG. 3 is a schematic perspective configuration diagram of a conventional carbon dioxide gas laser device.

[Explanation of symbols]

1 Laser head (microwave circuit) 5 Cylindrical conductor (parallel two wires) 6 transparent plate 7 mesh 10 Conductor wall 12 Dielectric 13 discharge space

Claims (2)

[Claims] 1. A microwave circuit for generating a microwave electric field for discharging a gas laser medium by microwave discharge to excite a laser, and a conductor wall forming a part of the microwave circuit; The gas laser medium is enclosed in a space formed between a dielectric body that is provided as an incident window for microwaves provided opposite to the conductor wall, and the dielectric body and the gas laser medium are enclosed by the microwave circuit. A gas laser device in which a microwave mode having an electric field component perpendicular to the boundary with is formed, wherein two parallel lines are used in the microwave circuit. 2. The gas laser device according to claim 1, wherein the microwave circuit is provided with an observation window for observing a discharge state and an internal state.