JPH065957A - Transversely-pumped laser oscillator - Google Patents

Abstract

PURPOSE:To stabilize a discharge from a main electrode without providing an auxiliary electrode in a casing by preliminarily ionizing gas between main electrodes by AC-discharging between the main electrodes, and then DC- discharging the main electrodes to excite a laser light ray. CONSTITUTION:A voltage of an AC power source 6 its first applied to main electrodes 2, and gas between the electrodes 2 is preliminarily ionized. Then, a switch 9 is closed to apply a voltage of a DC power source 4 to the electrodes 2. Thus, since a discharge is started from the electrodes 2, a laser light ray is excited. Overheated electrodes 2 are cooled by a conduit 3, and a high speed convection is generated in the gas in a casing 1 due to a temperature difference between the cooled electrodes 2 and the gas overheated due to the discharge, and hence the gas is circulated in the casing. Since the preliminary electrodes and a fan which have been heretofore provided are omitted, an assembling operability of a laser oscillator is improved, and yet a flow of the circulated gas is not disordered.

Description

Detailed Description of the Invention

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.

2. Description of the Related Art Conventionally, as a laterally pumped laser oscillator, a pair of main electrodes provided in a casing, a plurality of sets of auxiliary electrodes provided in the casing, a gas interposed in an internal space of the casing, A power supply for applying a required voltage to the main electrode and the auxiliary electrode is provided, and the auxiliary electrode is discharged to preionize the gas between the main electrodes and then the main electrode is discharged to excite a laser beam. The structure is known (for example, Japanese Patent Laid-Open No. 61-13679). In the above conventional laser oscillator, by providing the auxiliary electrode in addition to the main electrode, the stable region of discharge by the main electrode can be expanded to the high power density side.

However, the conventional laser oscillator described above has a drawback that the work of assembling the laser oscillator is complicated because the auxiliary electrode is additionally provided in the casing. Moreover, since the provision of the auxiliary electrode causes disturbance in the flow of the gas circulating in the casing, there is a risk that the discharge by the main electrode may be hindered. Further, since the dust is generated from the preliminary electrodes due to the discharge between the preliminary electrodes, there is a drawback that the stability of the discharge is impaired.

In view of the above-mentioned circumstances, the present invention provides a pair of main electrodes provided in a casing, a gas interposed in the internal space of the casing, and a required voltage applied to the main electrodes. A transverse excitation laser oscillator configured to AC discharge the main electrode to pre-ionize the gas between the main electrodes and then DC discharge the main electrode to excite a laser beam. It is provided.

With this structure, the stability of the discharge from the main electrode can be improved without providing the auxiliary electrode in the casing. Moreover, since the preliminary electrode does not exist in the casing, the assembling property of the laser oscillator is improved as compared with the conventional one, and the gas flow is not disturbed. Further, since the dust is not generated due to the spare electrode, the life of the gas can be extended as compared with the conventional case.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the illustrated embodiments. FIG. 1 shows an electric circuit of a laterally pumped laser oscillator. The laser oscillator includes a casing 1 containing a gas (not shown). A main electrode 2 composed of a pair of electrodes 2a and 2b is provided in the casing 1. Further, as will be described later, in this embodiment, since the main electrode 2 can also be used as a spare electrode, the spare electrode conventionally provided in the casing 1 is omitted. As shown in FIG. 2 in an enlarged manner, each electrode 2a, 2b of the main electrode 2 in this embodiment is formed in a plate shape, and one flat surface of each of the plate-shaped electrodes 2a, 2b is opposed to each other. Both electrodes 2 which have been made to face each other
The distance between a and 2b is set close to a distance of 10 mm or less. On the other hand, on the surfaces of the electrodes 2a and 2b that do not face each other, grooves are formed in the longitudinal direction, that is, in the direction orthogonal to the paper surface, and the conduit 3 as a heat exchanger is mounted in the grooves. ing. The conduit 3 is connected to a cooling medium supply source provided outside the casing 1,
By circulating a cooling medium such as water or oil from the supply source into the conduit 3, both electrodes 2a and 2b are cooled. In this embodiment, as described above, both electrodes 2
The distance between a and 2b is set to only a few millimeters, and the main electrode 2 is cooled so that the temperature rise is suppressed. Therefore, a temperature difference occurs between the gas between the main electrodes 2 whose temperature has risen due to the discharge and the surface of the main electrode 2.
Natural convection occurs inside. Therefore, in the present embodiment, the fan for gas circulation, which is conventionally provided in the casing 1, is omitted, whereby the casing 1
Is downsized. Further, in this embodiment, by omitting the preliminary electrode provided in the conventional casing 1, it is possible to suppress the deterioration of the gas and prolong the life of the gas.
Therefore, in this embodiment, when assembling the laser oscillator,
It is possible to operate by supplying a required amount of gas into the casing 1 and sealing it for a long time. As shown in FIG. 1, the main electrode 2
Is connected to the DC power supply 4 and at the same time connected to the AC power supply 6 via the coil 5. This AC power supply 6
Can supply a high voltage of several 10 KHz to several 100 KHz to the main electrode 2. In the present embodiment, first, a high AC voltage is applied to the main electrode 2 from the AC power source 6 to pre-ionize the gas between the main electrodes 2, and then several tens of ns later, the DC power source 4 applies a DC voltage to the main electrode 2. Is applied to cause a main discharge of the main electrode 2 to excite a laser beam. That is, between the DC power source 4 and the main electrode 2, a switch 9 is provided on the most upstream side and a main capacitor 10 for main discharge is provided, and a saturable reactor 11 is provided downstream of the main capacitor 10. It is provided. The saturable reactor 11
A spare capacitor 12 for capacity transfer is provided between the downstream side of the switch and the downstream side of the switch 9, and an inductor 13 is provided downstream of the spare capacitor. The saturable reactor 11 has a function of causing a deviation in current and voltage when the switch 9 is turned on, reducing the power applied to the switch 9, and thereby reducing the load applied to the switch 9. In the above configuration, first, the voltage of the AC power supply 6 is applied to the main electrode 2, and the gas between the main electrodes 2 is preionized. Next, the switch 9 is turned on, and the voltage of the DC power supply 4 is applied to the main electrode 2 via the main capacitor 10. As a result, discharge is started from the main electrode 2, and the laser beam is excited as in the conventional case. Then, the overheated main electrode 2 is cooled by the conduit 3 shown in FIG. 2, and high-speed convection occurs in the gas in the casing 1 due to the temperature difference between the cooled main electrode 2 and the gas overheated due to discharge. The gas is circulated in the casing 1. According to the present embodiment described above, since the preliminary electrode and the fan which are conventionally provided in the casing 1 are omitted, the workability of assembling the laser oscillator is improved, and the preliminary electrode circulates in the casing 1. There is no turbulence in the gas flow. further,
By omitting the preliminary electrode and the fan, the casing 1 itself can be downsized, and thus the laser oscillator can be downsized. Also, casing 1
Since the preliminary electrode does not exist inside, dust is not generated due to the preliminary electrode. Therefore, deterioration of the gas in the casing 1 can be suppressed and the life of the gas can be extended. Further, since the dimension between the electrodes 2a and 2b is narrowed as described above, the reflection from the inner surface of the casing 1 of the shockwave generated by the discharge is generated by the electrodes 2a and 2b.
It is possible to prevent intrusion between a and 2b. Therefore, it is possible to eliminate the adverse effect of the shock wave during discharge. (Second Embodiment) Next, FIG. 3 shows a second embodiment of the present invention. In the second embodiment, on the premise of the configuration of the electric circuit of the first embodiment, Instead of the conduit 3 provided in each of the electrodes 2a and 2b of the first embodiment, a conventionally known fan 116 and heat exchanger 117 are provided in the casing 101. The other structure is the same as that of the first embodiment, and the members corresponding to the respective members of the first embodiment have the member numbers added with 100. Also in the second embodiment having such a configuration, since the spare electrode is omitted from the inside of the casing 101, the workability of assembling the laser oscillator is improved, and the spare electrode prevents the gas circulating in the casing 101 from flowing. There is no turbulence in the flow. (Third Embodiment) FIG. 4 shows a third embodiment of the present invention. In the third embodiment, the configuration of the AC power supply 106 side in the second embodiment shown in FIG. 3 is changed. It was done. That is, the ring coil 218 and the matching unit 219 are used instead of the coil 105 in the second embodiment. Other configurations are the above second
This is the same as the embodiment, and the members corresponding to the respective members of the second embodiment have the member numbers added with 100. The third embodiment as described above can also obtain the same effects as the second embodiment. (Fourth Embodiment) Finally, FIG. 5 shows a fourth embodiment of the present invention. In the fourth embodiment, while the switch 209 in the third embodiment is omitted, the casing 20
The internal structure of No. 1 is the same as that of the first embodiment. That is, since the switch is omitted, the coil 320 is provided instead of the main capacitor 210, and the ring coil 318 is provided downstream of the auxiliary capacitor 312 in parallel therewith. When the laser is oscillated, a small current is supplied from the AC power supply 306, and the main electrode 3
A preliminary discharge is generated between 02a and 302b. afterwards,
The current of the AC power supply 306 is suddenly and rapidly increased. As a result, the main electrodes 302a and 302b are electrically connected to each other, the energy stored in the capacitor 312 flows, and main discharge is performed. In the fourth embodiment, each member corresponding to the third embodiment and the first embodiment has 100 or 300, respectively.
The member number is added. According to the fourth embodiment, it is clear that the same effect as the first embodiment can be obtained.

As described above, according to the present invention, the assembling properties of the laser oscillator are improved as compared with the conventional ones, and the gas flow is not disturbed. Further, it is possible to obtain the effect that the life of the gas can be extended as compared with the conventional case.

[Brief description of drawings]

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

FIG. 2 is a detailed enlarged view of a main part of FIG.

FIG. 3 is a circuit diagram showing a second embodiment of the present invention.

FIG. 4 is a circuit diagram showing a third embodiment of the present invention.

FIG. 5 is a circuit diagram showing a fourth embodiment of the present invention.

[Explanation of symbols]

 1 Casing 2 Main electrode 4 DC power supply 6 AC power supply

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Fumihiko Miyamoto, Furuhiko Miyamoto, Kanazawa City, Ishikawa Prefecture 58, Soybean Tamoto-cho, Shibuya Industry Co., Ltd. Within

Claims (1)

[Claims] 1. A pair of main electrodes provided in a casing,
The main electrode is provided with a gas interposed in the inner space of the casing and a power source for applying a required voltage to the main electrode.
A laterally pumped laser oscillator, characterized in that a C-discharge is performed to pre-ionize the gas between the main electrodes, and then the main electrode is DC-discharged to excite a laser beam.