JPS63228778A - Gas laser device - Google Patents

Abstract

PURPOSE:To prevent the temperature rise of a laser gas, and to reduce contamination by mounting a dielectric to the discharge surface of one main electrode and setting up a pre-ionizing electrode at the center of the dielectric. CONSTITUTION:A recessed section is formed at the center of the discharge surface 12a of one main electrode such as a cathode 12 in main electrodes 11, 12 and a dielectric 14 is fitted, a plate shaped pre ionizing electrode 15, a nose section of which is protruded from an inserting hole 12b, is installed at the central section of the dielectric 14, and a high voltage power 10 is connected on the base end side. When the high voltage power 10 is operated, the pre-ionizing electrode 15 is applied, creeping discharge is generated through the upper section of the surface of the dielectric 14, and UV beams are generated uniformly extending over the upper section of the surface of the dielectric without generating arc discharge, thus reducing the contamination of a gas laser.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Field of Application) The present invention relates to a gas laser device that excites laser gas by discharge and outputs laser light.

(Prior Art) In a typical gas laser device, a main electrode consisting of an anode and a cathode is provided in a laser tube containing a laser gas such as a CO2-N2-1-16 mixed gas. , the laser medium is excited by the discharge energy generated in this main mold. At the same time, the main discharge is stabilized by pre-ionizing the discharge space with a pre-ionization device before the main mold starts discharging.

Conventionally, the preliminary ionization method for the above-mentioned 1-meter pre-charge device includes the use of corona tri-electrons, ultraviolet rays, or X-rays.

A gas laser device using the above-described preliminary ionization method using ultraviolet light (hereinafter referred to as UV light) will be explained with reference to FIG. In the figure, 1 contains CO2-, for example, as a laser gas.
This is a laser tube filled with N2+-1e mixed gas. Inside the laser tube 1, an anode 2 and a negative cover 3, which serve as a pair of main electrodes, are provided extending in the direction in which laser light is generated.

Discharge surfaces 2 of the anode 2 and cathode 3 facing each other
A tli electric space portion 4 is formed between a and 3a.

Furthermore, a fan 5 is provided within the laser tube 1 to circulate the laser gas within the laser tube 1.

This fan 5 circulates the laser gas deteriorated by the discharge between the main electrodes 2 and 3 in a direction substantially perpendicular to the laser beam oscillation direction.

Further, a heat exchanger 6 for cooling the sea 11 gas is provided in the middle of the circulation path.

On the upstream side of the discharge space 4 in the laser gas circulation direction, there are provided a plurality of pairs of bottle electrodes 7 for pre-ionizing the discharge space 4 by using the V light generated by the arc discharge. . The pair of bottle actuators 7... are provided in parallel to the discharge direction of the main electrode 2.3 with their tips facing each other, and are arranged in plural pairs at a constant distance apart in the laser beam oscillation direction.

Furthermore, on the downstream side of the discharge space 4 in the laser gas circulation direction, a plurality of pairs of bottle electrodes 8 similar to the above-mentioned bottle electrodes 7 are arranged. Further, beaking condensers +j9... are provided in the middle of each of these bottle electrodes 7..., 8....

Then, by disturbing the high voltage power supply 10 provided outside the laser tube 1, the bottle electrodes 7..., 8...
A potential difference occurs between the tips of each of the capacitors 9 and 9, causing an arc discharge, thereby charging the peaking capacitors 9. U light is generated by this arc discharge, and the discharge space 4 is pre-ionized. Then, the reserve 11 of the discharge space section 4
1! When l advances enough, positive tfi2 and negative 1fl! 3, a main discharge due to glow discharge occurs and laser light is oscillated.

Here, the gas laser device as described above is
Preliminary ionization is performed by generating an arc discharge between the tips of the bottle electrodes 7, but since the laser gas reaches a high temperature up to the point t where this arc discharge occurs, sputtering occurs at the tips of the bottle electrodes 7, causing the laser gas to It has the property of polluting.

Therefore, in a gas laser device having such a structure, the laser gas containing as many products as the repetition rate increases is sent to the discharge space 4 by the fan 5, so that the main discharge is likely to become an arc discharge, resulting in stable laser light. will not be obtained. In other words, as shown in curve A shown in Fig. 4, the laser output increases linearly at low repetition rates, but at 200 (PP
From S) onwards, the output no longer increases and eventually decreases. Considering this around 200 (PPS) as the maximum number of repetitions, CR[[(gas circulation wind speed)/(number of repetitions)×
(main discharge width)], the field was as large as 8 to 10, and there was a limit to obtaining the effect of improving the optical output of the sea 11 by high-speed circulation of the laser gas.

(Problems to be Solved by the Invention) As described above, a typical gas laser device has a backup electric current I! provided on the upstream side in the gas feeding direction in the discharge space between the main electrodes. ! Due to the discharge of the electrode, contaminated laser gas flows into the discharge space, making the main discharge unstable and reducing the output of laser light.

This invention eliminates contamination of the laser gas due to pre-ionization on the upstream side of the laser gas in the discharge space, enables high repetition rate, and expands the range in which the U light is generated, significantly improving the output of the laser light. The purpose is to provide a gas laser device.

[Structure of the invention]

(Means and effects for solving the problem) This invention has the following features:
A discharge space is formed between at least a pair of main electrodes arranged in a laser tube in which laser gas is maintained at a predetermined pressure, and 71! By providing a dielectric material in the electric field and providing a pre-ionization electrode in the center of the dielectric material, a creeping discharge is generated between the one main electrode and the pre-ionization electrode on the surface of the dielectric material, and the laser gas The present invention provides a gas laser device which can reduce contamination of the gas and significantly improve the supply of U light to the discharge space, thereby obtaining high-output laser light.

(Embodiment) A first embodiment of the present invention will be described with reference to FIGS. 1 to 4. Since the basic groove structure of the gas laser device is almost the same as the conventional example described above, the same components will be explained. The same reference numerals are used to omit the explanation.

In the figure, 1 is a laser tube in which laser gas is sealed at a predetermined pressure. A pair of main electrodes 11 and 12 are provided in the laser tube 1 and are spaced apart from each other in the laser beam oscillation direction. At the center of the discharge surface 12a of the cathode 12 of one of the main electrodes 11, 12, for example, a belt-shaped recess 13 is provided extending in the laser beam oscillation direction.

The recess 13 is formed narrower than the discharge surface 12a. Further, a dielectric 14 formed to correspond to the shape of the recess 13 is fitted into the recess 13 .

Here, when the discharge surface 12a is formed to have a width of, for example, 1Q mm, the width of the dielectric 14 is formed to be, for example, 6 to 9 mm.

The dielectric 14 is made of, for example, Pyrex glass.
It is made of glass epoxy or alumina ceramic. A pre-ionization electrode 15 in the shape of a plate 1 is provided in the center of the dielectric 14, the tip of which protrudes from an insertion hole 12b formed through the dielectric 14 in its thickness direction.

This pre-ionization electrode 15 has an edge portion protruding from the center portion in the width direction of the dielectric material 14, and is provided facing in the laser beam oscillation direction. The inner wall of the insertion hole 12b of the cathode 12 and the pre-ionization electrode 15 are electrically insulated by insulators 16.

Also, the above preliminaries! A high voltage power source 10 is connected to the base end side of the electrode 15. And the cathode 12 is
The cathode 12 is connected to a holding plate 18 that holds the anode 11 with conductivity via a holding plate 17 that holds the cathode 12 with conductivity. A peaking capacitor 19 is provided in the middle of the wiring between the holding plates 17 and 18.

Furthermore, the wiring led out from the holding plate 18 is introduced and connected to the high voltage power supply 10.

Further, inside the laser tube 1, a fan 5 for circulating laser gas and a heat exchanger 6 for cooling the laser gas are provided.

Then, by making the above-mentioned high voltage power supply 10,
A pre-ionization electrode 15 is applied on the surface of the dielectric 14 with the cathode 12 and the creepage l! Generates electricity. This creeping discharge is the third
As shown in the figure, UV light is generated over substantially the entire surface of the dielectric 14 between the pre-ionization electrode 15 and the cathode 12, so that UV light can be generated without causing arc discharge.

Therefore, compared to the conventional preliminary ionization by arc discharge, discharge products are generated less, so that contamination of the laser gas can be reduced.

This creeping discharge supplies electrons onto the discharge surface 12a of the cathode 12, and the UV light photoionizes the discharge space 4 to generate electrons, which are pre-ionized.

On the other hand, the current from the high-voltage power supply 10 is charged to the peaking capacitors 19 through the pre-ionization electrode 15 and the anode 12. Then, when the preliminary ionization of the discharge space 4 and the charging of the peaking capacitors 19 are sufficiently performed, a main discharge occurs between the main electrodes 11 and 12. This main discharge occurs even in the area where the dielectric 14 is provided.
4, a stable glow discharge can be generated between the discharge surfaces of both the main electrodes 11 and 12.

Further, since contamination of the laser gas can be reduced by preliminary ionization caused by uniform creeping electrons, a more stable main discharge can be generated.

This type of gas laser device can significantly reduce contamination of the laser gas compared to pre-ionization using a conventional bottle electrode, so even if the circulation speed of the laser scum remains the same as before, it is possible to perform higher repetition rates than before. It is. For this reason, C
The R value was significantly improved to 4 to 4.5. Further, by providing the dielectric 14 on the discharge surface 12a of the main electrode 12 and providing the pre-electrode 113Il electrode 15 in the center of the dielectric 14, pre-ionization can be performed over a wide range, and the dielectric 14 can be pre-ionized over a wide range during main discharge. Since the main discharge occurs even in the portion where the main electrodes 11 and 12 are provided, a uniform glow discharge can be generated over substantially the entire discharge surface of the main electrodes 11 and 12. These effects enable high repetition rates and
As shown by curve B in the figure, the repetition rate is improved to more than twice that of the conventional method, thereby making it possible to significantly improve the laser light output.

Note that this invention is not limited to the above. For example, although the dielectric 14 and the pre-ionization electrode 15 are provided on the cathode 12, they may also be provided on the anode 11. In other words,
Any material may be used as long as it is provided on either one of the pair of main electrodes.

In this case, when the dielectric 14 and the preliminary 1ift electrode 15 are provided on the anode 11, it goes without saying that the configuration of the electric circuit needs to be changed. Furthermore, the widths of the cathode 12 and the dielectric material 14, which serve as one of the main mold depressions, are not limited to those described above.

A second embodiment according to the present invention will be described below, but since its basic configuration is the same as the first embodiment shown in FIG. 1, FIGS. Refer to and explain.

In FIG. 5, reference numeral 20 denotes one main electrode, and a dielectric material 22 is provided at a substantially intermediate portion of the discharge surface 21 of this main electrode 20 in the direction of laser beam oscillation.

In the center of the dielectric 22, a plate-shaped pre-drawn ionizer (edge part 23) is provided so that the edge part of the dielectric 23 protrudes. The opposing edge 24 facing the is formed in a wavy shape,
As a result, a plurality of pin edges 25 are provided that protrude toward the pre-ionization Ntf 123 side. By arranging the pin edges 25 uniformly in the laser beam oscillation direction, ignition is prevented uniformly and stable discharge can be obtained.

Further, as shown in FIG. 6, by arranging a plurality of bottle-shaped preliminary ionization electrodes 26 at a certain distance in the laser beam oscillation direction, a uniform creeping discharge can be obtained.

Roughly speaking, as shown in FIG. 7, the pre-ionization electrodes 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, and 27 are arranged in the direction of laser beam oscillation.
A plurality of pin edges 30 are provided that protrude to the side and have tapered tips. With this configuration, creeping discharge is caused by the pre-ionization electrode 27...
This occurs between ・and pin edge 30... A more stable creeping discharge can be generated across the laser beam oscillation direction, and the laser output can be further improved.

Note that this invention is not limited to the above. For example, the pre-ionization electrode in the second embodiment is plate-shaped or bottle-shaped, but is not limited thereto. In other words, it is sufficient to have a preliminary electrode 11 that is installed at a substantially medium temperature of the dielectric 22 and can generate a creeping current between it and one of the main electrodes 20, for example, a plate-shaped preliminary Nwi electrode that is simply divided into a plurality of electrodes. etc. are also included. Further, as described above, the present invention also includes a structure in which an inductance L is connected in series to each of the plurality of sub-electrodes 1111 to prevent pre-ionization discharge from turning into arc discharge.

A third embodiment of the present invention will be described below with reference to FIG.

In the figure, 31 is a laser medium such as CO2.
- It is a laser tube in which a laser gas such as N2-He mixed gas is sealed. Inside the laser tube 31, a pair of main electrodes 32 and 33 facing each other are provided extending in the oscillation direction of the ray+f light.

A discharge space 34 is formed between the main electrodes 32 and 33 with a certain distance between them.

Of the pair of main electrodes 32 and 33, for example, a recess 35 is provided on the discharge surface 33a of the cathode 33 in the laser beam oscillation direction. A dielectric 36 corresponding to the shape of the recess 35 is fitted into the recess 35 .

A plate-shaped preliminary ionization electrode 37 is provided at a substantially medium temperature of the dielectric 36 in the direction of laser beam oscillation. This pre-1i1i[electrode 37 is provided with its edge portion protruding from the dielectric 36 toward the 11i electric space portion 34 side. And 1a N located within the shadows 1 to 33
The m-electrode 37 is electrically insulated by an insulator 38.

In addition, the above-mentioned Yin-Yang 33 and the Yang (
- 32 are supported within the laser tube 31 via three holding plates 40 each having conductivity.

A laser tube 3 is attached to a holding plate 40 that supports the cathode 33.
1 is connected to a high voltage power source 41 provided externally, and furthermore, the three holding plates 40 are connected to each other via peaking capacitors 42 . Further, a wiring extending from the holding plate 39 and having a corona capacitor 43 in the middle is connected to the base end of the pre-ionization type If 137.

In addition, the wiring led out from the three holding plates is connected to the high voltage power source 4.
1 is installed and connected.

High voltage power supply 41 of the gas laser V device formed in this way
When the peaking capacitor 42 is operated, the peaking capacitor 42...
is charged directly. Then, the cathode 33 and the pre-electric current
The corona capacitor 43 is charged by a creeping discharge occurring through the surface of the dielectric 36 between the I electrode 37 and the I electrode 37 . The discharge space 34 separated by a predetermined distance due to the creeping discharge is filled with the peaking capacitor 42 which is sufficiently charged.
A glow discharge is generated by applying a voltage from the source, and a laser beam is oscillated.

By configuring as described above, the corona capacitor 4
By changing the capacity of No. 3, the amount of discharge during preliminary ionization can be adjusted.

A fourth embodiment of the present invention will be described below with reference to FIG. 9. Since its basic structure is substantially the same as that of the third embodiment shown in FIG. 8, the same components are the same. to avoid focusing on explanations and only explain the improvements.

In the figure, 33 is, for example, a cathode serving as one main IJi, and this cathode 33 is provided in a not-shown laser tube in a pair with an anode 32.

A dielectric 36 is provided on the discharge surface 33a of the cathode 33, and a pre-ionization electrode 37 is provided at the center of the dielectric 36. A condenser capacitor 43 is provided in the middle of the wiring 44 that connects the holding plate 39 that deeply supports the anode 32 and the preliminary illumination electrode 37. Further, a timing switch 45 is provided between the holding plate 39 of the arrangement [144] and the corona capacitor 43.

In this way, the switch 45 for pre-ionization timing
When operating a gas laser S device equipped with
By controlling the switch 45 to close after the battery 2 is sufficiently charged, a high electric field is suddenly applied between the cathode 33 and the pre-ionization electrode 31, and creeping discharge can be uniformly generated. Here, in addition to the method in which the switch 45 is provided to determine the timing, there are also methods in which the timing is determined by the distance between the bin electrodes, and a method in which an arrester is used.

Note that the present invention is not limited to the above embodiments. For example, in each of the above embodiments, the base end of the pre-ionization type ti is buried in the dielectric, but the structure is not limited to this, and it is provided approximately in the center of the dielectric, with one main electrode and Any device may be used as long as it generates a creeping discharge on the surface of the dielectric, and includes, for example, a device having a preliminary ionization electrode provided on the surface of the dielectric and wired from the end of the main electrode.

〔Effect of the invention〕

As explained above, according to the present invention, a dielectric is provided on the discharge surface of one of the main electrodes, and a preliminary ionization electrode is provided approximately in the center of this dielectric. In order to generate a creeping discharge, the distance between the pre-ionizing electrodes is increased, and the current can be discharged uniformly over the dielectric surface without concentrating and causing arc discharge. Due to this effect, the range of M radiation can be greatly expanded compared to the conventional structure, and stable and uniform Uv light can be generated over a wide range. Furthermore, in the past, the laser gas was significantly contaminated by pre-ionization caused by arc discharge, but by pre-ionization caused by uniform creeping discharge as described above, contamination can be significantly reduced by preventing the slave from becoming too hot. . Furthermore, although the dielectric is faced to the flt electric current of one of the main electrodes, during the main discharge between the main electrodes, the main discharge also occurs through the dielectric.
The main discharge can be generated in substantially the same manner as in the conventional method while obtaining the above-mentioned effects. Due to the above-described effects, it is possible to provide a CAST laser device that can oscillate a laser beam with extremely high output compared to the conventional structure.

[Brief explanation of the drawing]

1 to 3 show a first embodiment of the present invention, in which FIG. 1 is a front cross-sectional view of a laser beam oscillation device seen from the laser beam oscillation direction, and FIG. 3 is a plan view showing the discharge state of the discharge surface of one of the main electrodes, and FIG. 4 shows the relationship between the laser output and the number of repetitions between the gas laser device of the conventional structure and the laser according to the present invention. Graphs comparing the devices, FIGS. 5 to 7, show the second embodiment of the present invention. Each figure is a plan view showing improved N poles for pre-ionization, and FIG. 8 is the second embodiment of this invention. FIG. 9 is a front sectional view showing the mounting portion of the fourth embodiment of the invention, and FIG. 10 is a front sectional view showing the structure of a conventional general gas laser device. It is. 1...laser tube, 4...fi? ! Space section, 11...
・Anode (main electrode), 12... Cathode (main electrode), 12a
...Discharge surface, 14...Dielectric material, 15...Preliminary electric a
mmli. Applicant's Representative Patent Attorney Takehiko Suzue Figure 1 Figure 2 Figure 4rIJ Figure 5 ts6 Figure 7 Figure 8

Claims (2)

[Claims] (1) a laser tube in which laser gas is maintained at a predetermined pressure; at least a pair of main electrodes disposed facing each other in a spaced manner within the laser tube; and a discharge space formed between these main electrodes;
A dielectric body provided along the longitudinal direction of one of the discharge surfaces of the pair of main electrodes; A gas laser device comprising a pre-ionization electrode that pre-ionizes the discharge space by generating a creeping discharge. (2) The gas laser device according to claim 1, wherein the discharge surface of one main electrode forms a plurality of pin edges whose tips protrude toward the preliminary ionization electrode side.