JP2745990B2 - Laterally pumped laser oscillator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a laterally pumped laser oscillator that performs pulse oscillation.

[0002]

2. Description of the Related Art FIG. 4 shows an electric circuit of a conventional laterally pumped laser oscillator. The voltage of a DC power supply (not shown) is applied to a main capacitor 1 where electric charges are stored.
The charge stored in the main capacitor 1 is transferred to the trigger circuit 2
When the thyratron 3 is turned on, the operation is shifted to the sub capacitor 4. A pair of main electrodes 5 and a large number of spare electrodes 6 arranged on both sides of the main electrodes 5 are arranged in a casing 7 in which gas for laser oscillation is sealed. When the transition is made, first, an arc discharge occurs in the gap of the spare electrode 6,
The ultraviolet rays generated there ionize the gas between the main electrodes 5.
When the electric charge is transferred to the sub-capacitor 4, the voltage between the two electrodes of the sub-capacitor 4 increases, and the voltage between the main electrodes 5 connected in parallel with the sub-capacitor 4 also increases. When the voltage between the main electrodes 5 reaches the breakdown voltage, the electric charge stored in the sub-capacitor 4 flows into the main electrodes 5, and a glow discharge occurs between the main electrodes 5 to excite the gas.

[0003]

However, since the breakdown voltage between the main electrodes 5 is mainly determined by the distance between the main electrodes 5 and the gas pressure, the laser energy can be efficiently used even if the voltage of the main capacitor 1 is increased. Does not rise. That is, even if the voltage of the main capacitor 1 is increased,
Since the breakdown voltage is reached before the charge is sufficiently transferred to the sub-capacitor 4 and the discharge at the main electrode 5 is started, even if the voltage of the main capacitor 1 is increased, the efficiency of the laser energy can be increased efficiently. Does not lead to In addition, the electric charge remaining in the main capacitor 1 flows into the main electrode 5 after the end of the main discharge, so that the main discharge current flows to the main electrode 5 for a long time, and arc discharge occurs between the main electrodes. Cause it to occur. Further, the discharge of the spare electrode 6 is performed.
Gas deteriorates due to electricity and shortens the life of the gas
There are drawbacks. In view of the such circumstances, Ki out to increase the laser energy efficiently by raising the voltage of the main capacitor 1, yet provides long lateral <br/> directional pumping type laser oscillator life of gas Things.

[0004]

That is, the present invention provides a DC power supply connected to a main capacitor, and a sub-capacitor connected to the main capacitor via first switching means.
Via the second switching means a transversely pumped laser oscillator example Bei a main electrode connected to the sub condenser
This laterally pumped laser oscillator is separate from the main electrode.
Not equipped with a spare electrode of
By also in the range wherein the AC power supply use are connected.

[0005]

According to the above construction, by closing the first switching means with the second switching means opened, the electric charge stored in the main capacitor is transferred to the sub-capacitor via the first switching means. be able to. At this time, by opening the second switching means, the electric charge stored in the main capacitor can be sufficiently transferred to the sub-capacitor without causing discharge between the main electrodes. When the electric charge stored in the main capacitor is sufficiently transferred to the sub-capacitor, the first switching means is opened and the second switching means is closed to apply the voltage of the sub-capacitor to the main electrode. Therefore, a good glow discharge having a high peak value of the discharge current can be performed by the main electrode. As described above, since the electric charge stored in the main capacitor can be efficiently guided to the main electrode, the laser energy can be efficiently increased by increasing the voltage of the main capacitor. Also, the lateral excitation according to the present invention
Type laser oscillators do not have spare electrodes.
Suppress gas deterioration due to discharge of storage electrode and extend gas life
Can be longer.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. FIG. 1 shows an electric circuit of a laterally pumped laser oscillator according to the present invention.
The main capacitor 12 is connected to a sub-capacitor 14 via a first switching means 13.
And a pair of electrodes 16 via the second switching means 15.
a and 16b are connected. In the present embodiment, the main electrode 16 is configured to be able to be used also as a spare electrode. Therefore, a number of spare electrodes provided on both sides of the main electrode 16 in the related art are omitted, and the main electrode 16 is connected via a transformer 17 instead. Connected to an AC power supply 18. The AC power supply 18 can supply a high voltage of several tens KHz to several hundred KHz to the main electrode 16. The first switching means 13 has a common electrode 21 connected to the sub-capacitor 14 and a first electrode 22 separated from the common electrode 21 by a predetermined distance and connected to the main capacitor 12. The first trigger pin 23 is adjacent to the gap between
The trigger circuit 24 is connected to the first trigger pin 23. On the other hand, the second switching means 15 includes the common electrode 21 described above and a second electrode 25 separated from the common electrode 21 by a predetermined distance and connected to one electrode 16a of the main electrode 16. The second trigger pin 26 is adjacent to the gap 25, and the trigger circuit 24 is connected to the second trigger pin 26. The main electrode 16 is provided in a casing 31 in which a gas for laser oscillation is sealed. On the other hand, the first switching means 13 and the second switching means 15 are provided in a casing 32, and xenon is provided in the casing 32. The mixed helium gas is sealed.

In this embodiment, first, an AC high voltage is applied from the AC power supply 18 to the main electrode 16 to pre-ionize the gas between the main electrodes 16. At this time, since the second switching means 15 is open, the charge from the AC power supply 18 is not supplied to the sub-capacitor 14, and the gas between the main electrodes 16 can be efficiently pre-ionized. . When the gas between the main electrodes 16 is pre-ionized, the number 1
After 0 ns, a high DC voltage is applied from the DC power supply 11 to the main electrode 16, whereby the main electrode 16 is subjected to main discharge to excite the laser gas. When applying a high DC voltage to the main electrode 16 from the DC power supply 11, first, the first switching means 1
From the state where the third switching means 15 and the second switching means 15 are respectively opened and the electric charge from the DC power supply 11 is stored in the main capacitor 12, the trigger circuit 24 keeps the second switching means 15 open and the first switching means 1
By closing 3, the electric charge stored in the main capacitor 12 can be transferred to the sub-capacitor 14. The fact that the charge stored in the main capacitor 12 has been sufficiently transferred to the sub-capacitor 14 means that the main capacitor 12
And a voltage dividing resistor 34 provided for measuring the voltage of the sub-capacitor 14.
Can be detected by measuring the respective voltage values V ₁ and V ₂ . When it is detected that the electric charge stored in the main capacitor 12 is sufficiently transferred to the sub capacitor 14, the first switching means 13 is opened by the trigger circuit 24 and the second switching means 1 is opened.
5 is closed, and sufficient electric charge transferred to the sub capacitor 14 is applied to the main electrode 16. At this time, as described above, since a high AC voltage is applied to the main electrode 16 from the AC power supply 18 and the gas between the main electrodes 16 is pre-ionized, the charge transferred to the sub-capacitor 14 is transferred to the main electrode 16. , It is possible to cause the main electrode 16 to perform a good glow discharge having a high discharge current peak value. The discharge current at this time can be detected by the coil 35 provided adjacent to the main electrode 16. Thus, the first switching means 13 and the second switching means 1
5, the electric charge stored in the main capacitor 12 can be efficiently guided to the sub-capacitor 14 first, and then to the main electrode 16 at that time. Obtained by closing
Therefore, even if the voltage of the main capacitor 12 is increased, there is no adverse effect as in the prior art, and the laser energy can be efficiently increased by increasing the voltage of the main capacitor 12.

FIG. 2 shows the main part of the electric circuit shown in FIG. 1 in concrete form. In FIG. 2, a casing 31 for accommodating the main electrode 16 has an open left side. A casing 32 for accommodating the first switching means 13 and the second switching means 15 has an open right side. The casings 31, 32 and the middle plate 38 are integrally connected to each other with a middle plate 38 interposed between the openings of the two casings 31, 32, thereby forming a sealed chamber in each of the casings 31, 32. . The casings 31, 32 and the middle plate 38 are made of a conductive material, and are used as an electrical ground. A plurality of tapered holes 39 for positioning are provided at the lower portion of the casings 31 and 32, respectively. The tapered holes 39 are formed on a plurality of conical positioning tapered pins 41 fixed to the frame 40. By mounting, the frame 4
The casings 31 and 32 can be accurately positioned at zero. In this state, the casings 31 and 32 are connected to the frame 4 by bolts (not shown).
It is fixed to 0. Each of the electrodes 16a and 16b of the main electrode 16 provided in the casing 31 is formed in a plate shape, and the electrodes 16a and 16b are spaced from each other by a distance of 5 mm or less. 16b are integrally connected to each other by a plurality of insulating spacers 43. Further, a groove is formed in the surface opposite to the opposing surface of the electrodes 16a and 16b in the longitudinal direction, that is, in the direction orthogonal to the paper surface, and a conduit 44 as a heat exchanger is formed in the groove. Attached. Each conduit 44 is connected to a cooling medium supply source provided outside the casing 31,
By flowing a cooling medium such as water or oil from the supply source into the conduit 44, the electrodes 16a and 16b can be cooled. Electrode 1 constituting main electrode 16
6a and 16b, one electrode 16b is connected to the middle plate 3 by a plurality of support bars 45 made of a conductive material.
8 to connect the electrode 16b to ground. On the other electrode 16a, a support rod 46 made of one or more conductive materials is integrally attached to a surface opposite to the opposing surface of both electrodes,
The support rod 46 is supported by an insulating bush 47 made of an insulating material fixed to the middle plate 38.
The support rod 46 penetrates through the insulating bush 47 and protrudes into the other casing 32, and is connected to a second electrode 25 provided in the casing 32 as described later.

Next, a common electrode 21 formed of a cylindrical body is provided in the other casing 32 described above, and the common electrode 21 is provided with a plurality of support bars 51 made of a conductive material via a sub-capacitor 14. We support in. Both ends of the common electrode 21 are separated from the wall surface of the casing 32, and the space inside and outside the common electrode 21 communicate with each other via the gap. The common electrode 21
Inside the common electrode 21, a rod-shaped first electrode 22 constituting the first switching means 13 together with the common electrode 21 is provided.
And are provided in parallel. Both ends of the first electrode 22 are respectively supported by the casing 32 via an insulating material 52, and one end of the first electrode 22 is projected outside the casing 32 and connected to the main capacitor 12. One or more first trigger pins 23 are attached to the casing 32 with an insulating material 53 interposed therebetween, and the tip of the first trigger pin 23 is bored in the cylindrical common electrode 21. The common electrode 21 and the first electrode
It extends to an intermediate position of the gap with the electrode 22. The first trigger pin 23 is of course connected to the trigger circuit 24 as shown in FIG. Inside the casing 32, a rod-shaped second electrode 25 constituting the second switching means 15 together with the common electrode 21 is provided outside the cylindrical common electrode 21. The second electrode 25 is disposed parallel to the common electrode 21 at a distance from the common electrode 21 toward the middle plate 38, and both ends of the second electrode 25 are attached to the casing 32 via an insulating material 55. As described above, the support rod 46 provided on the electrode 16a is connected to the insulating bush 4 fixed to the middle plate 38.
7 and protrudes into the casing 32, and is slidably provided on the support rod 46, and is connected to the second electrode 25 by a conductive spring 56 so as to elastically contact the second electrode 25. And the electrode 16a are electrically connected. The connection terminal 57 is connected to the AC power supply 18, and the tip of one or more second trigger pins 26 attached to the casing 32 via an insulating material 58 is connected to the common electrode 2.
It is located at a position adjacent to the gap between the first and second electrodes 25.

The basic operation of the embodiment shown in FIG. 2 is as described with reference to FIG. 1. In this embodiment, the common electrode 21 is formed in a cylindrical shape, and the first electrode 22 is provided inside the common electrode 21 and the second electrode 2 is provided outside.
Since the space 5 is provided, the discharge space between the electrodes 21 and 22 and the discharge space between the electrodes 21 and 25 in the common casing 32 can be partitioned by the cylindrical common electrode 21 as much as possible. Therefore, the electrons generated by each discharge,
Mutual adverse effects due to ions, temperature, and the like can be prevented. In the present embodiment, as described above, both electrodes 16a,
The interval of 16b is set to a narrow interval of 5 mm or less, and further, the main electrode 16 is cooled so that a rise in gas temperature between the main electrodes 16 is suppressed.
That is, a temperature difference is generated between the gas between the main electrodes 16 whose temperature has increased due to the discharge and the surface of the main electrode 16,
The gas between the main electrodes 16 is cooled while flowing naturally between the main electrodes 16 at high speed. Further, a part of the gas between the main electrodes 16 which has been heated to a high temperature by the discharge is released from the space between the main electrodes 16 due to thermal expansion. , The gas between the main electrodes 16 is exchanged. Therefore, in the present embodiment, the gas circulation fan provided in the conventional casing 31 is omitted, and the casing 31 is downsized. Further, in this embodiment, the conventional casing 3
Since the spare electrode provided in 1 is omitted, the deterioration of the gas due to the discharge of the spare electrode can be suppressed, and the life of the gas can be extended. Therefore, in this embodiment, when assembling the laser oscillator, a required amount of gas is supplied to the casing 31.
It is possible to supply the gas to the inside and to operate for a long time while sealing.

FIG. 3 shows still another embodiment of the present invention. In the embodiment shown in FIG. 2, a second electrode 25 is provided separately from the electrode 16a of the main electrode 16. In this embodiment, the electrode 16a of the main electrode 16 is also used as the second electrode. That is, in this embodiment, the middle plate 38 is manufactured from an insulating material.
An opening 38a is formed in the housing 1 and the opening 38a is closed in an airtight manner by an electrode 16a directly attached to the middle plate 38 on the casing 31 side.
6a is also used as the second electrode, and is adjacent to the common electrode 21 on the casing 32 side. Further, the conductive support bar 45 connected to the other electrode 16b and the conductive support bar 51 for supporting the common electrode 21 via the sub-capacitor 14 keep the insulating middle plate 38 airtight. Are connected to each other via a connection terminal 61 penetrated therethrough, and the connection terminal 61 is connected to the ground. In the embodiment shown in FIG. 2, the second electrode 25 and the electrode 16a
, The floating inductance in the discharge circuit of the sub-capacitor 14 becomes relatively large.
When the stray inductance increases, the pulse width of the current flowing through the main electrode 16 increases, whereby the peak of the current value decreases, leading to a decrease in the laser output, and the discharge easily transitions to arc discharge. On the other hand, according to the present embodiment, the stray inductance can be reduced, so that arc discharge hardly occurs.

[0012] A contact configuration of switching means 13, 14 is not intended to be limited to the above embodiments, may be any configuration if it has the above functions. Further, in the embodiment shown in FIG. 2, the inner electrode of the cylindrical common electrode 21 is the first electrode 22 and the outer electrode is the second electrode 25, but both may be reversed.

[0013]

As is evident from the foregoing description, according to the present invention, it is possible to direct the charge stored in the main capacitor efficiently main electrode, Ki out to increase the laser energy efficiently, also preliminary electrode Is not provided,
Gas life and prolong gas life.
The effect of wear can be obtained.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing one embodiment of the present invention.

FIG. 2 is a detailed sectional view of a main part of FIG. 1;

FIG. 3 is a sectional view showing another embodiment of the present invention.

FIG. 4 is a conventional circuit diagram.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 11 ... DC power supply 12 ... Main capacitor 13 ... First switching means 14 ... Sub capacitor 15 ... Second switching means
16: Main electrode 16a, 16b: Electrode 18: AC power supply
21 common electrode 22 first electrode 25 second electrode

Claims (3)

(57) [Claims] A DC power supply of claim 1 was connected to the main capacitor, and a sub capacitor connected to the main capacitor through the first switching means and via a second switching means e Bei a main electrode connected to the sub condenser Lateral excitation type
A laser oscillator, wherein the laterally pumped laser oscillator
Does not have a spare electrode separate from the main electrode, and
A laterally pumped laser oscillator, wherein an AC power supply for preliminary ionization is connected to the main electrode . 2. A common electrode formed of a cylindrical body, a first electrode disposed inside the common electrode and separated from the common electrode,
A second electrode disposed outside of the common electrode and spaced apart from the common electrode, and one of the first switching means and the second switching means is switched by the common electrode and the first electrode. but the common electrode and the transverse excitation type laser oscillator <br/> paragraph 1, wherein the scope of the claims other switching means by the second electrode is characterized by being composed respectively. 3. A common electrode formed of a cylindrical body, a first electrode disposed inside the common electrode and separated from the common electrode,
A first main electrode disposed outside of the common electrode at a distance from the common electrode, wherein the first switching means is provided by the common electrode and the first electrode, and a second switching means is provided by the second electrode by the common electrode and the main electrode. transverse excitation type laser oscillator according to paragraph 1 claims, characterized in that the switching means are constituted respectively.