JPH01302787A - Gas laser oscillation equipment - Google Patents

Abstract

PURPOSE:To uniformize preparatory ionization density, and reduce the jitter of discharge pulse by a method wherein, prior to main discharge between main electrodes, preparatory ionization electrodes for preparatory ionization between the main electrodes are subjected to preparatory ionization by using auxiliary preparatory ionization electrodes. CONSTITUTION:A voltage applied to main electrodes 13, 14 by closing a high voltage switch 19 is equal to a voltage generating between both ends of a charging coil 18. When this voltage exceeds the firing potential of a pin electrode 23, auxiliary preparatory ionization discharge generates. By generation of the auxiliary preparatory ionization discharge, the pin electrode 21 is subjected to preparatory ionization, preparatory ionization discharge generates, and spark discharge generates. By ultraviolet rays generated by the spark discharge, the main electrodes 13, 14 are subjected to preparatory ionization. Between the main electrodes 13, 14, uniform glow discharge generates, and laser light generates.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a gas laser oscillation device having a preliminary M electrode such as a bottle electrode that pre-ionizes a gas laser medium between main electrodes.

(Prior Art) For example, a CO2 gas laser oscillation device is configured as shown in FIGS. 6 and 7, and a gas medium (CO2-N2-He
(a mixture of gases) is enclosed. Inside the discharge tube 1, main electrodes 2.3 are arranged facing each other along the longitudinal direction at predetermined intervals.

These main electrodes 2.3 are supported by a support plate 4.5,
A high voltage power supply (not shown) is connected, and a high voltage is applied between the main electrodes 2 and 3.

A charging coil 6 is connected in parallel between this high voltage power supply and the main electrode 2.3, and a main capacitor 7 is connected in series.

Furthermore, the main capacitor 7 is connected between the high voltage power supply (not shown) and the charging coil 6 and the main capacitor 7.
A high-voltage switch 8 is provided that supplies electrical energy stored in a pulsed manner.

Furthermore, a pair of mirror bodies (not shown) are provided on the outside of the discharge tube 1 to reflect light generated by discharge between the main electrodes 2 and 3. One of these mirrors is a high-reflection mirror, and the other is an output mirror that transmits light with a predetermined output or higher, and by arranging these mirrors with high parallelism to each other, an optical resonator is created. is formed.

A plurality of bin electrodes 9, . . . as child R ionization electrodes are arranged at equal intervals on the left and right portions of each of the main electrodes 2.3, and these bin electrodes 9, . Peaking capacitors 10, . . . are installed on my anode side.

Then, when a voltage is applied by the high voltage power supply,
First, spark discharge is generated between the bottle electrodes 9, . This spark discharge is caused by the main electrode 2 having a longitudinal direction.
．． However, the spark discharge between the bottle electrodes 9, . . . occurs simultaneously in the longitudinal direction of the main electrodes 2 and 3. For example, as shown in Fig. 4, three bottle electrodes 9, etc. installed at different positions have different times when the bottle spark current reaches its maximum. In other words, there is slight variation in the distance between the bin electrodes 9, etc., and the discharge start times are not simultaneous, but have a certain time width.Also, when a discharge occurs, there is always a spark. There is a statistical lag.

Therefore, during the main discharge 2.3, non-uniform B ionization density and jitter with respect to the discharge pulse appear.

Such unstable pre-ionization cannot be expected to improve efficiency, and has the drawback that, for example, when several laser oscillators are operated in synchronization, output pulses become distorted.

(Problems to be Solved by the Invention) There are slight variations in the distance between the plurality of secondary Fi electric electrodes provided on the side near the main electrode, and the discharge start time is not simultaneous but has a certain time interval. I had.

This has disadvantages in that the oscillation efficiency of the laser beam of the gas laser oscillator cannot be improved and that output pulses are distorted when several laser oscillators are operated synchronously.

This invention has been made in view of the above-mentioned problems, and provides a gas laser that suppresses variations in the start time of pre-ionization discharge at the pre-ionization electrode, equalizes the pre-ionization density, and at the same time reduces the jitter of the main discharge pulse. The purpose is to provide an oscillation device.

[Structure of the invention]

(Means for solving the problem) Main electrodes are provided facing each other in a discharge cabinet in which a gas laser medium is sealed, a high voltage power source is connected to these main electrodes, and electrical energy from the high voltage power source is temporarily supplied. A storage capacitor is provided, and a high voltage switch is provided to supply the electrical energy stored in the capacitor in a pulsed manner.
Optical resonators are provided that face each other with the discharge space in between, and a pre-ionization electrode is provided that pre-ionizes the space between the main electrodes prior to the generation of the main discharge between the main electrodes. This is in a gas laser oscillation device equipped with an M electrode.

(Function) Prior to the generation of the main discharge between the main electrodes, the pre-ionization electrode that pre-ionizes the space between the main electrodes is pre-ionized using a splint (fW ionization electrode). Pre-ionization between the electrodes can be performed simultaneously, making the pre-ionization density uniform and at the same time reducing the jitter of the discharge pulse.

(Example) A first example of the present invention will be described with reference to the drawings. A gas medium (for example, CO
2-N2-He mixed gas) is sealed at a predetermined pressure.

Main electrodes 13 and 14 are provided within the discharge tube 12, and their discharge surfaces face each other at a predetermined interval. These main electrodes 13 , 14 are arranged parallel to each other in the longitudinal direction and are supported by support plates 15 , 16 fixed within the discharge tube 11 . A high voltage power source 17 is connected to the main electrodes 13 and 14. A charging coil 18 and a high voltage switch 19 are provided in parallel between the high voltage power supply 17 and the main electrodes 13 and 14, respectively. A capacitor 20 is connected in series.

On the other hand, a plurality of first bin electrodes 21, . . . as preliminary ionization electrodes are provided at equal intervals along the longitudinal direction on the sides of the main electrodes 13, 14. The base ends of these first bottle electrodes 21, . . . are coupled to the support plates 15, 16, respectively, and the two electrodes are disposed in pairs with their distal ends facing each other. For example, first peaking capacitors 22, . . . are provided in the middle of the first bottle electrodes 21, . , . . . are connected with wiring from the high voltage power supply 17, similarly to the main electrodes 13, 14, respectively.

Further, on the outer side of the first bottle electrodes 21, . . . , a plurality of second bottle electrodes 23 as splint-equipped ionization electrodes,
...is arranged. These second bin electrodes 23
,... are located between the first bin electrodes 21,..., and a second peaking capacitor 24,... is located halfway between the second bin electrodes 23,... on the anode side.・ is provided. And the second bottle electrode 23,...
- The distal ends are opposed to each other in a pair, and the proximal ends are coupled to the support plate 15.16 and electrically connected to the high voltage power source 17 in the same way as the main electrodes 13.14.

Here, the gap size between the first bottle electrodes 23, . . . is set to about 3 ml, and the gap size d of the second bottle electrodes 23, . It is set. Furthermore, the capacitance of the first peaking capacitors 22, . . . is larger than the capacitance of the second peaking capacitors 24, .

When a gas laser is oscillated by the gas laser oscillation device 1 configured as described above, the high voltage power supply 17
is applied in a pulsed manner by the high voltage switch 19, and by applying this voltage,
The second bin electrode 23, which is provided with a peaking capacitor 24 of... splints fli! Ionization discharge (referred to as sub-pre-ionization discharge to distinguish the discharge generated at the lower-side pre-ionization electrode from other discharges) is generated. Since the gap size d between the bottle electrodes is as short as about 0.511, this sub-preliminary ionization discharge generates a pin spark discharge at a low interelectrode voltage. Therefore, the ultraviolet light intensity is low and the pre-ionization ability is also low.

Therefore, although the first bottle electrodes 21, . . . have the ability to pre-ionize, they cannot pre-ionize the main electrodes 13, 14. Here, when the high voltage switch 19 is closed, the voltage applied to the main electrodes 13, 14 is approximately equal to the voltage V generated across the charging coil 18. The voltage V generated across the charging coil 18 is proportional to di/dt, and the change in current flowing through the electric circuit connecting the high voltage power supply 17 and the main electrode 13.14 is proportional to di/dt.
If the inductance of 8 is L, the voltage V applied to the main electrode 13.14 is expressed as V-L (di/dt).

When this voltage V exceeds a predetermined discharge starting voltage of the second bin electrodes 23, . . . , a sub-preliminary ionization discharge is generated.

Then, due to the generation of this sub-preliminary ionization discharge, the first bottle electrodes 21, . These first bottle electrodes 21, . . . have a gap D between the electrode surfaces of about 3n, and generate spark discharge at a higher voltage than the second bottle electrodes 23, . and the first
The bottle electrodes 21, . . . pre-ionize the main electrodes 13, 14 with ultraviolet rays generated by the spark discharge.

Here, since the second bottle electrodes 23,... generate spark discharge at a low voltage, the second bottle electrodes 23,...
・Jitter can be reduced.

Then, due to the spark discharge generated almost simultaneously throughout the entire body, the first pin electrode 2 disposed in the longitudinal direction
1. Splint ionize uniformly. A bottle spark discharge is generated at the first pin electrodes 21, . . . after a time interval of several ns from the generation of discharge at the second bottle electrodes 23, .

The main electrodes 13, 14 are pre-ionized by the pin spark discharge of the first pin electrodes 21, .
．． 14, a homogeneous glow discharge is generated in the longitudinal direction. This glow discharge brings about an oscillation state between the optical resonators that do not cause a discharge, and when the laser light exceeds a predetermined output, the laser light is output from the output mirror side.

By performing the splint ionization as described above, the discharge starting voltage of the first pin electrodes 21, .

As a result, jitter with respect to the discharge start time of the first pin electrodes 21, . . . can be reduced, and the main electrode 13
．． Homogeneous preionization can be carried out simultaneously over the entire length of 14. This state will be explained with reference to FIG. The figure shows the discharge state of the three pin electrodes 21, . . . with time on the horizontal axis and the spark spark current of the first pin electrode 21, . . . on the vertical axis. It can be seen that the pin spark discharge at each pin electrode 21, . . . ends in an extremely short time compared to the conventional structure shown in FIG.

In this way, by completing the discharge of all the first pin electrodes 21, . also prevents the output pulse from being disturbed.
can be accurately synchronized.

A second embodiment of the present invention will be described below with reference to FIG. 3, but since its basic structure is the same as that of the first embodiment, only the different parts will be explained in detail.

A gas medium is sealed in the discharge tube 12 of the gas laser oscillation device 25 shown in the figure at a predetermined pressure, and main electrodes 13 and 14 are faced to each other at a predetermined distance from each other within the discharge tube 12. The main electrodes 13.14 are arranged in parallel with each other in the longitudinal direction.These main electrodes 13.14 are each connected to a support plate 15.16, and are connected to a high voltage provided on the outside of the discharge tube 12. It is connected to a power source 17.

A charging coil 18, a high voltage switch 19, a main capacitor 20, etc. are provided between the main electrodes 13, 14 and the high voltage power supply 17.

Furthermore, a plurality of pin electrodes 21, .
... the first peaking capacitor 22 in the middle,
... are provided for each.

A plurality of corona electrodes 26, . . . as splint-equipped ionization electrodes are disposed outside the pin electrodes 21, . These corona electrodes 26 are provided, for example, on the support plate 16 on the anode side, and their tips are connected to the first
The pin electrodes 21, . . .

With this configuration, the corona electrode 26,
... generates ultraviolet rays by generating corona discharge,
The first pin electrodes 21, . . . are splinted and ionized. By providing such corona electrodes 26, . . . as splint rB ionization electrodes, variations in the start time of the pre-ionization discharge of the pin electrodes 21, . By making the density uniform, the jitter of the discharge pulses of the main electrodes 13 and 14 can be reduced.

In addition, how many layers of splint #! Similar effects can be obtained by using electrodes that are provided with electrodes that generate creeping discharge in addition to the pin electrodes 23, . . . and the corona electrodes 26, . . . shown in the above embodiments.

〔Effect of the invention〕

By providing a splint ionization electrode that pre-ionizes the pre-ionization electrode, it is possible to prevent variations in the discharge start time of the pre-ionization electrode and to equalize the pre-ionization density, thereby increasing the discharge pulse of the main electrode. Jitter can be reduced.

[Brief explanation of the drawing]

1 and 2 show a first embodiment of the present invention, and FIG. 1 is a front cross-sectional view showing a schematic configuration of a gas laser oscillation device, and FIG. 2 is a view taken from the direction of line ■-■ in FIG. 3 is a front sectional view showing the schematic configuration of the gas laser oscillation device of the second embodiment of the present invention, and FIG. 4 is a pin spark of the pre-ionization electrode of the conventional gas laser oscillation device. FIG. 5 is a diagram showing the relationship between time and pin spark current, showing the relationship between current and time. FIG. 5 is a diagram showing the relationship between time and pin spark current of the pre-ionization electrode in this invention. FIG. 6 is a schematic diagram of a gas laser oscillation device with a conventional structure. A front cross-sectional view showing the configuration, FIG. 7 shows the main electrode of the conventional structure and the main electrode.
FIG. 3 is a side view showing the configuration of the poles. 12...Discharge tube, 13.14...Main electrode, 17...
・High voltage power supply, 19... High voltage switch, 20...
Main capacitor, 21...first bottle electrode (preliminary ionization electrode), 23...second bottle electrode (splint ionization electrode)
, 26...Corona electrode (splint-equipped ionizing electrode). Applicant's agent Patent attorney Takehiko Suzue Figure 4 Figure 5 Figure 6 Figure 7-

Claims (1)

[Claims] A discharge tube in which a gas laser medium is sealed at a predetermined pressure, a main electrode provided facing inside the discharge tube, a high-voltage power supply that supplies electrical energy to these main electrodes, and a A storage capacitor, a high-voltage switch that supplies electrical energy stored in the capacitor in a pulsed manner, an optical resonator formed by mirrors facing each other with the discharge tube in between, and the main electrode. In a gas laser oscillation device equipped with a pre-ionization electrode that pre-ionizes between the main electrodes prior to a main discharge, a sub-preliminary electrode that pre-ionizes the pre-ionization electrode prior to a discharge that pre-ionizes a space near the pre-ionization electrode. A gas laser oscillation device characterized by being provided with an ionization electrode.