JPH02290090A - Q switch laser device - Google Patents

Abstract

PURPOSE:To facilitate adjustment by providing a source voltage control circuit which controls the voltage of a high frequency circuit in a Q switch laser device and making the laser output of a switch first pulse weak. CONSTITUTION:In a Q switch element drive circuit 8, a clock signal 15 which is generated by a Q switch oscillation timing circuit 9 is inputted in a source voltage control circuit 14 and is divided into a signal 16 that is lacking in the first pulse and a signal 17 that has the first pulse only. On the other hand, a high frequency signal 18 given from a high frequency generating circuit 10 is modulated by the signal 16 in a high frequency amplification circuit 11. Further, the signal 17 given from the circuit 14 controls the voltage of a source circuit 13 and the output of the circuit 11. The output signal 21 of the circuit 11 is given to the Q switch element 5 of a laser oscillator 1 and makes the initial peak value of a laser output that is outputted by the oscillator 1 small. This approach facilitates adjustment without being affected by a clock signal.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a Q-switched laser device.

[Prior art] Conventionally, a Q-switched laser device has a Q-switch element drive circuit that drives a Q-switch element as shown in Fig. 4(a). By using the attenuated control signal 26 as shown in b), the output signal 27 for driving the ultrasonic Q-switch element is controlled as shown in FIG. As shown in , the laser output signal 28, which has a large peak value compared to the steady state that occurs in the initial stage of the Q-switched laser, is weakened, and the Q-switched laser is started after the laser output signal 28 is at the same level as the laser output 29 after the steady state output is obtained. was oscillating.

[Problem to be solved by the invention]

In the conventional Q-switch laser device described above, in order to control the clock input signal of the Q-switch element drive circuit as shown in FIG. 4(b), the ultrasonic Q-switch element drive output signal 27 that generates a high frequency is amplified. It is susceptible to the influence of the clock input signal when it is used, and there are restrictions on control time, waveform control, etc. Therefore, it takes time to adjust the high frequency amplifier circuit and the impedance matching circuit.

In addition, the control time is limited because it takes time for the laser not to oscillate from signal input to laser oscillation.
There is a drawback in that when using the device, it is necessary to time the device drive from signal input to laser oscillation.

The present invention aims to solve these problems of the conventional devices, and provides a Q-switched laser device that is not affected by a clock signal and is easy to adjust.

[Means to solve the problem]

The Q-switched laser device of the present invention includes a resonant mirror, a laser medium, a Q-suinochi element, an excitation source for exciting the laser medium, a power supply for the excitation source, and a Q-switch based on a clock train that determines the Q-switch oscillation timing. In a Q-switch laser device comprising a Q-switch element drive circuit that drives a switch element, the Q-switch element drive circuit includes means for controlling the Glucose train so as to weaken its first noculus when Q-switch oscillation starts. It is characterized by containing.

〔Example〕 Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a block diagram of a Q-switched laser device which is an embodiment of the present invention.

The Q-switched laser device shown in FIG. 1 includes resonator mirrors 2 and 3 constituting a laser oscillator 1, a laser medium 4, a Q-switch element 5, an excitation source 6 for exciting the laser medium, and an excitation power source 7. and a drive circuit 8 that drives the Q switch element.

To explain the Q-switch element drive circuit 8 in more detail, this circuit includes a Q-switch oscillation timing circuit (clock circuit) 9, a high-frequency generation circuit 10, a high-frequency amplification circuit 11, an impedance manoching circuit 12, and a power supply circuit. 13
and a power supply voltage control circuit 14.

FIG. 2 shows a timing diagram showing the operation of this device. The clock signal 15 shown in FIG. 2(a) generated by the OQ switch oscillation timing circuit (clock circuit) 9 is input to the power supply voltage control circuit 14, This results in a signal 16 lacking the first pulse in FIG. 2(b) and a signal 17 containing only the first pulse in FIG. 2(c). The high-frequency signal 18 shown in FIG. 2(d) generated by the high-frequency generating circuit 10 is generated by the missing first pulse of FIG. The signal 16 is modulated to produce a modulated signal 19 shown in FIG. 2(.).

On the other hand, the single pulse signal 17 in FIG. 2(C) from the power supply voltage control circuit 14 controls the voltage of the power supply circuit 13 in FIG.
The output of the latter stage of the high frequency amplifier circuit 11 is controlled as shown in 21 in FIG. 2(g).

Q-switch oscillation occurs at the falling edge 22 . of the modulated high frequency signal 21 in FIG. 2(g). 23, but the second
When the fall of the modulated high-frequency signal 21 in Figure 2 (g) is 923, it takes time for the fall to occur, so the peak value of the output laser output suddenly falls as shown in Figure 2 (h). It's smaller than 31, like 30.

In the above embodiment, the power supply circuit 13 is the first pulse.
, the output voltage 20 and the clock pulse train 16 below the second pulse are created separately, and the high frequency output signals 21, 22, 23 (FIG. 2(f)) are formed in two stages within the high frequency amplifier circuit ll. However, this is because the output voltage 20 of the triangular wave Hals and the chronograph signal 16 of the rectangular wave pulse are different, so dividing them into two stages will simplify the circuit.

However, if the signal shown in FIG. 3 is created by combining the above two types of IP pulses and directly modulates the high frequency signal 18, the circuit becomes complicated, but the falling signal 22 of the modulated high frequency Yoshi also stands down for a short time. Therefore, the peak value of the laser output in the steady state of the Q switch becomes strong and stable.

In this embodiment, since a laser output with a large peak value can be obtained, there is an advantage that processing characteristics are improved.

〔Effect of the invention〕

As explained above, the present invention adds a power supply voltage control circuit for controlling the voltage of the high frequency circuit to the Q switch laser device and weakens the laser output of the first noculus of the Q switch, thereby producing a J, Q switch oscillation timing signal. (Black,
This has the effect of enabling easy-to-adjust first-pulse control, which is affected by the frequency of the clock signal).

This device has the effect of improving productivity in the field of laser rimming, where the workpiece is delicate and the machining characteristics are affected by changes in the output of the laser device.

circuit.

[Brief explanation of drawings]

Fig. 1 is a block diagram of one embodiment of the present invention, and Fig. 2 is a block diagram of an embodiment of the present invention.
FIG. 3 is a timing diagram of the circuit shown in the figure, FIG. 3 is a timing diagram of the second embodiment, and FIG. 4 is a timing diagram of the conventional device. Explanation of symbols: 1...Laser oscillator, 2, 3...Resonator mirror, 4...Laser medium, 5...Q switch element, 6...Excitation source, 7...Power source for excitation ,8...Q
Switch element drive circuit, 9... Q switch oscillation timing circuit (clock circuit), 10... High frequency generation circuit, 11... High frequency amplification circuit, 12... Input dance matching circuit, 13... Power supply Circuit, 14...Power supply voltage control-692-

Claims (1)

[Claims] 1. A resonator mirror, a laser medium, a Q-switch element, an excitation source that excites the laser medium, a power source for the excitation source, and a Q-switch that drives the Q-switch element based on a clock train that determines the Q-switch oscillation timing. In a Q-switched laser device comprising a switch element drive circuit, the Q
A Q-switch laser device, characterized in that the switch element drive circuit includes means for controlling the pulse train so as to weaken the first pulse at the time of starting Q-switch oscillation.