JPS5933278B2 - solid state laser device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a solid-state laser device having a Bockel cell Q-switch.

A solid-state laser device having a Pockel cell Q switch for obtaining a shear acid pulsed laser beam usually has five configurations as shown in FIG.

That is, a solid-state laser oscillation element, for example, ruby rod 1
A spiral excitation light source flash lamp 12 around the 1
are arranged, and mirrors 13a and 13b for optical resonators are arranged on both ends of the ruby rod 11 in the longitudinal direction, and between one mirror 13b and the ruby rod, a deflection plate 14, a Bottskel cell 15, and a Pockels cell are arranged. A Pockel cell Q switch 11 including a switching device 16 for applying a control voltage is provided, and a lamp switching device 18 including a power source for causing the flash lamp 12 to emit light is connected to the flash lamp 12. Is 19 Potsuker cell Q switch 1? ) and a control pulse generator that applies control pulses to the lamp switching device 18.

In the device shown in FIG. 1, the lamp switching device 18 generates a high-voltage trigger pulse in response to a control pulse from the control pulse generator 19 to cause the flash lamp 12 to start emitting light, which is delayed for a certain period of time from this trigger pulse. Then, the Bockel cell Q switch 11 operates to generate a shear acid pulsed laser beam, which is taken out as an output from the mirror 13a. The electrical circuit system for this switching is shown in FIG. 2, and FIG. 3 shows a time chart of pulse waveforms at various parts as time passes. 1st
The pulse generator 1 is started by manual operation or by an external signal pulse 20, and generates a single start pulse 21. The second pulse generator 2 receives the start pulse 21 from the first pulse generator 1 and generates a high-voltage trigger pulse 22 that starts the excitation light source flash lamp 12, and the flash lamp 12 is connected to a separately prepared capacitor bank. The main discharge circuit including the main discharge circuit emits light at 2T to excite the laser medium. The delayed pulse generator 3 receives the start pulse 21 from the first pulse generator 1 and generates a delayed pulse 23 delayed by a preset fixed time td. The third pulse generator 4 receives the delayed pulse 23 from the delayed pulse generator 3, and generates a trigger pulse 24 whose waveform is shaped and amplified. The fourth pulse generator 5 receives the trigger pulse 24 from the third pulse generator 4 and switches the Bockels cell Q switch, so that a shear and pulse laser beam 28 is obtained. However, when the circuit is actually configured as shown in FIG. 2, the high voltage trigger pulse 22 generated by the second pulse generator 2 has a peak voltage of about 10 to 30 K, and the induced noise caused by this pulse is large.

In particular, the third pulse generator 4 uses a monostable multivibrator for pulse waveform shaping and a high impedance amplifier circuit, and this noise operates the monostable multivibrator and generates the same signal as the trigger pulse 24. It is easy to cause Further, in the high impedance amplifier circuit, this noise is amplified and tends to become a noise equivalent to the trigger pulse 24. Therefore, the time interval T as shown in FIG. 4b is applied to the fourth pulse generator 5. Two consecutive pulses will be input. However, although the fourth pulse generator 5 uses a high-speed switching element, such as a klytron or a hydrogen thyratron, the time interval is T. (about 1msec
A high-speed repeating switch operation at such a high speed is impossible due to the large time constant of the charging circuit including the Pockels cell. Therefore, the fourth pulse generator 5 cannot respond to each of the two consecutive pulse inputs, and the fast switching element switches at the pulse 26 generated by the first noise, and the second trigger pulse 24 Then, the switch will no longer occur and a malfunction will occur. As a result, shear and pulse laser light cannot be obtained. The present invention prevents malfunction of the pulse circuit caused by the high-voltage trigger pulse of the flash lamp as described above,
An object of the present invention is to provide a solid-state laser device that can obtain stable Q-switch oscillation.

According to the present invention, first, the signal line through which one or more pulses 29 due to noise as shown in FIG. Insert an open contact relay with delay time TR.

However, as shown in Figure 5b. Start pulse 21
It rises almost in synchronization with , and the pulse width is T. If we apply a pulse wider than
As shown in FIG. 3, one or more pulses 29 generated by noise are cut off because the relay contacts are open, and the trigger pulse 24, which is a normal signal, passes through and is output to the fourth pulse generator 5 described above. Malfunctions can be completely prevented. Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 6 shows a third pulse generator 4 and a fourth pulse generator 5 in the general control signal pulse generation circuit shown in FIG.
A malfunction prevention circuit 6 including a relay 7 is added to the signal line connecting the two. The drive circuit 8 of the relay 7 is
After receiving the start pulse 21 from the first pulse generator 1, there is a delay time T. A relay drive pulse having a longer pulse width than the above is generated to drive the coil of the relay 7 whose contacts are inserted into the signal line. If a monostable multivibrator of an integrated circuit is used as the relay drive circuit 8. An appropriate pulse width can be easily obtained using a resistor and a capacitor, and the operation delay time for the relay 7 is shorter than the delay time of the delay pulse 23 and longer than the pulse width of the trigger pulse 22, which is several hundred μS.
A suitable reed relay of EC grade is used. In this way, the effect of easily preventing circuit malfunctions due to noise using inexpensive components is great.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram of the configuration of a general solid-state laser device, Fig. 2 is a block diagram of a general control signal pulse generation circuit, Fig. 3 is a diagram of pulse waveforms generated in each part shown in Fig. 2, and Fig. 4 is a diagram of the pulse waveforms generated in each part shown in Fig. 2. The figure is a waveform diagram showing the relationship between a high-voltage trigger pulse a, a pulse generated by noise caused by the high-voltage trigger pulse, and a delayed pulse train b. Figure 5 is a waveform diagram explaining the operation of the relay used in the present invention. The figure is a block diagram of the control signal circuit of the apparatus of the present invention. 1...First pulse generation circuit, 2...Second pulse generation circuit, 3...Delayed pulse generation circuit, 4...Third pulse generation circuit , 5...
4th pulse generation circuit, 6...malfunction prevention circuit,
7... Relay, 8... Relay drive circuit, 11... Laser oscillation element, 12...
Flash lamp, 13a, 13b... Resonator mirror, 14... Deflection plate, 15... Bockel cell, 16... Switching circuit, 17
...Potsuker Cell Q Switch, 18...
・Lamp switching circuit, 19... Torch pulse generation circuit.

Claims (1)

[Claims] 1. A laser oscillation element, a flash lamp for irradiating the laser oscillation element with excitation light, a pair of resonator mirrors for obtaining laser oscillation, a Pocket cell Q switch for switching the laser oscillation, and the flash lamp. A high-voltage trigger pulse generation circuit that starts light emission, and a certain period of time delay from this high-voltage trigger pulse, the Pocket Q
A solid-state laser device equipped with a delay pulse generation circuit for operating a switch, a relay that closes its contacts after an operation delay time in a time range that is longer than the pulse width of the high-voltage trigger pulse and shorter than the delay pulse delay time;
A solid-state laser device, characterized in that it is inserted into a signal line through which the delayed pulse passes.