JPH01241880A - Laser device - Google Patents

Abstract

PURPOSE:To obtain a laser light having high quality and high output from a laser device of a single discharge tube by providing a plurality of pulse high voltage power sources connected in parallel between electrodes and a trigger circuit for sequentially repeatedly exciting the power sources at a predetermined time interval. CONSTITUTION:When a trigger synchronizing signal TRG having a predetermined period is applied to a trigger circuit 13, thyratrons T1 to Tn are sequentially discharged, a discharge tube 1 is excited by a high voltage pulse at each time, and this operation is repeated to oscillate a laser. After the thyratrons are discharged, a predetermined recovery time is required, but when the periods of trigger pulses Tg1, Tg2... and the like are set to a longer recovery time, the tube 1 is excited in a short period of time in which the thyratrons T1 to Tn are sequentially discharged even if next trigger pulse Tg is applied to one thyratron T after the lapse of the recovery time, thereby providing a large laser output.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to a laser device using metal vapor or gas as a laser medium, and particularly relates to a laser device with an improved electric circuit for generating electric discharge. .

(Prior Art) Conventionally, this type of laser device has been constructed mainly of a ceramic discharge tube 1 having excellent heat resistance, as shown in FIG.

The discharge tube 1 is supplied with He from the gas supply system 3 to the discharge section 2 inside the discharge tube 1.
, while a discharge buffer gas such as Ne is supplied,
It is evacuated by a rotary pump 4, and a cathode 5 and an anode 6 are disposed facing each other at both ends.

A pulsed high voltage from a pulsed high voltage power supply 7 is applied between the cathode 5 and the anode 6, and a pulsed discharge is performed between the two electrodes to generate discharge plasma. This pulsed high voltage has a voltage of several kV to 10-odd kV and a repetition frequency of kHz to 10-odd kHz.
It is z.

A plurality of metal particles 8 are arranged inside the discharge tube 1, and when the metal particles 8 come into contact with the discharge plasma, the discharge tube 1 is heated to a very high temperature and the metal particles 8 evaporate, thereby forming a laser medium. metal vapor is produced.

The metal vapor is uniformly distributed in the discharge tube 1 at a density of 10゛4~10''n/cn?, and when excited by free electrons in the discharge plasma, it emits light at a wavelength unique to the metal. This light passes through the window 9a of the casing 9, which is an envelope, and is amplified while reciprocating through an optical resonator consisting of an output mirror 10 and a total reflection mirror 11 placed on both sides of the discharge tube 1, and output. The laser beam is output from the mirror 10 side.

In the pulsed high voltage power supply 7, a charging resistor R and a peaking capacitor C2 are connected in parallel to the cathode 5 and an anode 6, and a thyratron 12 is connected to the cathode 5 in series with the charging capacitor C1. The anode of the thyratron 12 is connected to the positive side of a high voltage DC power supply via a diode D and a choke L, and the grid is connected to a trigger circuit (not shown).

(Problems to be Solved by the Invention) In a laser oscillation device that uses metal vapor or gas as a laser medium, the oscillation capacity of a single device is basically determined by the capacity of the discharge tube, but in order to efficiently extract that capacity, it is necessary to The condition is to increase the value of voltage x current x discharge repetition frequency.

Here, in order to improve the discharge repetition frequency, even if the frequency is simply increased, there are limitations due to the charging and discharging capacity and time constant of the thyratron 12. For this reason, in order to obtain high output with a conventional laser device, it has been common to combine a plurality of laser devices.

However, in this case, an increase in the number of devices leads to an increase in the size of the device, resulting in an increase in installation space and construction cost.

An object of the present invention is to provide a laser device that can increase laser output without increasing the number of laser devices.

[Structure of the invention]

(Means for Solving the Problems) The present invention includes a discharge tube in which the gas contained therein is heated by discharge and becomes a light emission source of a gas laser, and negative and negative electrodes respectively disposed on both ends of the discharge tube. , a laser device has a pulsed high voltage power supply connected between each of these electrodes, and a trigger circuit that excites this pulsed high voltage power supply, and a plurality of pulsed high voltage power supplies connected in parallel between the electrodes. and a trigger circuit that sequentially and repeatedly excites each pulsed high voltage power source at predetermined time intervals.

(Function) After a pulsed high voltage power supply is excited once and generates a pulsed high voltage, it requires a certain recovery time before it can be excited again and generate the next pulsed high voltage. Multiple pulsed high-voltage power supplies connected in parallel to the discharge tube are sequentially excited by a trigger circuit, and this is repeated, so even if the recovery time of each pulsed high-voltage power supply does not change, the discharge tube Since the discharge repetition frequency of can be made higher than the number of the plurality of lasers, the laser output can be increased while using one laser device.

(Example) An example of the present invention will be described below with reference to FIGS. 1 and 2.

FIG. 1 is a sectional view showing an embodiment of the present invention together with a circuit diagram of a pulsed high voltage power supply, and parts such as the discharge tube 1 other than the pulsed high voltage power supply 7 in FIG. 1 are shown in FIG. They are the same as those shown in FIG. 3, and are given the same reference numerals as in FIG. 3, and their explanation will be omitted.

In FIG. 1, a charging resistor R and a peaking capacitor C2 are connected in parallel between a cathode 5 and an anode 6 attached to a discharge tube 1. Moreover, between the cathode 5 and the anode 6,
A charging capacitor C1-1 and a thyratron T1 connected in series are connected. The anode of the thyratron T1 is connected to a high voltage DC power supply HV through a series circuit of a diode D1 and a choke L1. The negative side of the high voltage DC power supply is grounded GND and connected to the cathode and anode 6 of the thyratron T1. The grid of thyratron T1 is connected to a trigger circuit 13.

Furthermore, in addition to this, between the cathode 5 and the ground GND, there is a circuit including a charging capacitor C1-2, a thyratron T2, a diode D2, and a choke L2, which are configured the same as the circuit related to the thyratron T1 described above.
n- up to a circuit consisting of a charging capacitor C1-n, a thyratron Tn, a diode Dn, and a choke Ln.
One circuit is connected in parallel, and each grid from Thyratron T2 to Thyratron Tn is also connected to the trigger circuit 13, respectively. Here, the value of n is, for example, 5
etc. can be set as appropriate.

The details of the trigger circuit 13 are as shown in FIG.
It generates a trigger pulse Tgl which is frequency-divided into 1/n1/n and applied to the grid of thyratron T1 with a delay of the period of the trigger synchronization signal TRG. The trigger pulse Tg applied to the thyratron T can be generated up to Tgn.

Next, the effect of this will be described.

By applying a 1-trigger synchronization signal TRG of a constant period to the trigger circuit 13, trigger pulses Tgl, Tg2 and Tgn are generated sequentially at equal intervals as shown in FIG. Therefore, the thyratrons T1 to Tn sequentially discharge, each time exciting the discharge tube 1 with a high-voltage pulse,
By repeating this process, laser oscillation occurs as shown in the bottom row of FIG. The high-voltage pulse generation action by the discharge of each thyratron is similar to that known in the art, so a description thereof will be omitted.

Here, after the discharge of each thyratron, a certain recovery time is required as described above, but the trigger pulses Tgl, Tg2
By setting each period such as ・ etc. longer than this recovery time, as is clear from the middle row of Figure 2,
Although the next trigger pulse Tg is applied to one thyratron T after its recovery time has passed, the discharge tube 1 receives thyratrons T1 to Tn sequentially, as shown in the bottom row of FIG. It is excited in a short period during discharge, and therefore a large laser output can be obtained.

According to this embodiment, the following effects can be obtained.

1) High laser output that could not be obtained conventionally can be obtained with a single discharge tube.

2) Since it is not necessary to combine the laser beams of the laser device including a plurality of discharge tubes in order to obtain a high-power laser output, the optical system is simplified and the quality of the laser beam is improved.

3) Relatively high laser output can be obtained using a small pulsed high voltage power supply.

Note that although the above-mentioned embodiments have been described with respect to metal vapor lasers, these can be similarly applied to excimer lasers, carbon dioxide lasers, and the like.

〔Effect of the invention〕

According to the present invention, it is possible to obtain high-quality, high-output laser light from a single discharge tube laser device by adding a relatively simple configuration.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing an embodiment of the present invention in combination with a circuit diagram, Fig. 2 is a timing chart diagram explaining the operation of Fig. 1, and Fig. 3 is a conventional laser device used in combination with a circuit diagram. FIG. 1 Discharge tube 5.. Cathode 6. Anode 7.. Pulse high voltage power supply 13.
・1 Heliga circuit 18 = L-1-J Fig. 1

Claims (1)

[Claims] A discharge tube in which the gas contained therein is heated by discharge and becomes the light source of the gas laser, Yin and Yang electrodes installed at both ends of the discharge tube, and a pulsed high voltage power supply connected between these electrodes. and a trigger circuit for exciting this pulsed high voltage power source, the plurality of pulsed high voltage power sources connected in parallel between the electrodes, and each of the pulsed high voltage power sources being activated at predetermined time intervals. 1. A laser device comprising: the trigger circuit that sequentially and repeatedly excites the trigger circuit.