JPS62226683A - Gas laser device - Google Patents

Abstract

PURPOSE:To obtain a stable laser output by anew mounting a compensation circuit and compensating the temperatured dependency of a solar cell when a laser device is constitute of a gas laser oscillator, an oscillator drive power and the solar cell receiving one part of laser beams from the oscillator. CONSTITUTION:Voltage is applied to a laser tube l and a trigger circuit 4 by a laser power 6, pre-discharge is conducted by the trigger circuit 4 first, and stable discharge is performed. On the other hand, the greater part of oscillated laser beams 8 are transnitted through a half mirror 2, and emitted as output beams 8A, but one part is reflected by the mirror 2 and forwarded toward a solar cell 3 as reference beams 8B. In the constitution, a compensation circuit 7 is added to the outside of an oscillator 5 and fitted, and the temperature of the cell 3 is compensated and fed back to the power supply 6. Accordingly, even when the temperature of the cell 3 is elevated and output voltage is increased, an increasing section can be compensated, and a signal displaying only laser power car be transmitted over the power supply 6, thus keeping descharge currents in the tube l constant.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a gas laser device. More specifically, the present invention relates to an improvement in a gas laser device that performs feedback control based on the output signal of a solar cell for detecting light output.

Conventional gas laser devices excite gas atoms or molecules by pumping them, for example, by electron bombardment due to discharge, in a gas-filled laser tube.
It uses stimulated emission to generate laser oscillation.

Considering the principle of oscillation, a gas laser device generates a considerable amount of heat during oscillation. The laser light output during operation is unstable due to thermal deformation of the laser tube caused by this heat generation, fluctuation of the angle of the resonator mirror, consumption of gas in the laser tube, contamination of the optical window due to sputtering, etc.

Therefore, optical feedback control is carried out to stabilize the output of the laser beam by detecting the output of the laser beam oscillated by the gas laser device and controlling the discharge current in the laser tube based on the detected output. Since the output of the laser light emitted by a gas laser device is influenced by the discharge current in the laser tube, performing optical feedback control using the relationship between this discharge current and the laser light output stabilizes the laser light output. It is effective for

Therefore, conventional gas laser devices are equipped with a gas laser oscillator, a power source that drives the Gaslade oscillator, and a solar cell that receives part of the output laser light from the gas laser oscillator. In response to this, the applied voltage was changed to control the discharge current in the laser tube so as to keep the laser light output constant, thereby stabilizing the laser light output.

Problems to be Solved by the Invention However, in conventional optical feedback control, the output signal of the solar cell does not change as long as the incident laser power is constant, and the solar cell outputs a voltage signal proportional to the magnitude of the incident laser power. It was based on the assumption that it would always output. In other words, the feedback control depends on the characteristics of the solar cell, and the stability of the laser output can be said to depend on the stability of the solar cell.

However, the actual output of a solar cell has temperature dependence as shown in the graph of FIG. 2 when light of the same power is incident.

Therefore, when a laser device is operated using conventional optical feedback control, the output of the solar cell fluctuates depending on the environmental temperature. The output was actually fluctuating.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to correct the drawbacks of conventional gas laser devices as described above and provide a gas laser device that can obtain stable laser output without being affected by environmental temperature. be.

Means for solving the problem, ie, according to the present invention, a gas laser oscillator;
The device includes a power source that drives the gas laser oscillator, and a solar cell that receives a portion of the output laser light from the gas laser oscillator, and the power source receives the output signal of the solar cell and keeps the laser light output constant. In the gas laser device, the discharge current of the gas laser oscillator is controlled such that the discharge current of the gas laser oscillator is controlled such that the temperature detection means detects the temperature of the solar cell; A correction circuit that performs correction based on is further provided.

Function: In the gas laser device of the present invention, a correction circuit is provided as described above to compensate for the temperature dependence of the solar cell that detects the output laser beam, so it is possible to obtain a signal that accurately corresponds to the output laser beam. .

Therefore, accurate feedback control can be performed to maintain the laser output constant, and stable laser output can be obtained.

Embodiments Hereinafter, embodiments of a laser device according to the present invention will be described with reference to the accompanying drawings.

FIG. 11S1 is a block diagram illustrating a preferred embodiment of a gas laser device according to the present invention. The illustrated gas laser device has a laser tube 1 provided with internal reflection mirrors at both ends, and in front of the output side internal reflection mirror of the laser tube is a half mirror 2 that reflects a part of the output laser beam.
is arranged, and the solar cell 3 is placed so as to receive the reflected light.

Further, a trigger circuit 4 is connected to the anode of the laser tube 1. The above constitutes the laser oscillator 5.

One of the output terminals of the laser power source 6 is connected to the trigger circuit 4, and the other end of the power source 6 is connected to the trigger circuit 4 and the cathode of the laser tube 1.

With this configuration, when starting the laser tube, a preliminary discharge voltage is supplied from the trigger circuit 4 to obtain a stable discharge.
Following that, a discharge voltage is applied.

On the other hand, the output voltage of the solar cell 3 is supplied to a correction circuit 7, and the power supply 6 controls the discharge voltage based on the output voltage of the correction circuit 7. Although not shown in FIG. 1, this correction circuit 7 is equipped with a temperature detector that detects the temperature of the environment in which the solar cell 3 is placed in order to detect the temperature of the solar cell 3. , the output voltage of the solar cell 3 is corrected according to the environmental temperature detected by the temperature detector, and the power supply 6
supply to.

FIG. 3 is a circuit diagram showing an embodiment of the correction circuit 7. In FIG. The correction circuit 7 includes a correction voltage generation circuit and a comparison circuit that outputs the difference between the output voltage of the solar cell 3 and the output voltage of the correction voltage generation circuit. As shown in FIG. 3, the correction voltage generation circuit has a differential amplifier UPI, and the inverting input of the differential amplifier DPI is connected to a power source Ez.
The voltage is divided by the resistors Ra and Rd and input manually, and a feedback resistor Rb is connected between the inverting input and the output. The output thereof is grounded via a series circuit of a resistor Rc and a platinum resistance temperature sensor Rt, and a non-inverting input is connected to an intermediate connection point of the series circuit.

In the correction voltage generation circuit as described above, both yj and the platinum resistance temperature sensor RE have the following voltage ell (11)
It will be done.

ec+= gzEzRt/ (1g2RJ) However, g
2= (1+ Ra/Rd) Rb/RaRc its voltage e
Ll is connected to the inverting input of the differential amplifier OP2 via a resistor R2, and a feedback resistor R2 is further connected between the inverting input and the output. On the other hand, the voltage across a variable resistor R1 connected in parallel to the solar cell 3 is supplied to the non-inverting input of the differential amplifier 2 via a voltage divider circuit consisting of two resistors R2 connected in series. It is done like this.

In the above circuit, when the voltage across the resistor R1 is el, the output voltage e of the differential amplifier OP2 is. is eo”el
Represented by ell.

Since platinum has positive temperature characteristics, the resistance value increases as the temperature rises. Therefore, the voltage eL+ increases in the circuit as the temperature increases.

Therefore, as can be seen from FIG. 2, even if the environmental temperature rises and the voltage of the solar cell 3, that is, el increases, the voltage eLl also increases accordingly, so that the output voltage e of the correction circuit 7. (=e+e,) is not affected by temperature changes.

Next, the operation of the gas laser device according to the present invention will be explained. That is, first, a voltage is applied to the laser tube 1 and the trigger circuit 2 by the laser power source 4, a preliminary discharge is performed by the trigger circuit, and then a stable discharge is performed. On the other hand, most of the oscillated laser light 8 passes through the half mirror 2 and is output as output light 8A. However, a part of it is reflected by the half mirror 2 and is irradiated onto the solar cell 3 as reference light 8B.

The output voltage signal from the solar cell 3 is compensated for the temperature of the solar cell by the correction circuit 7 and fed back to the laser power source 6. At that time, the temperature of the solar cell increases,
Even if the output voltage of the solar cell increases, the increase due to temperature is compensated for, and a signal indicating only the laser power is supplied to the laser power source 6. Therefore, the laser power source 6 controls the discharge current in the laser tube 1 according to the manually inputted signal, and maintains the laser light output constant without being influenced by the temperature of the solar cell.

In this way, stable feedback control can be performed to maintain the laser output constant even if the temperature of the solar cell fluctuates.

Although the above embodiment is an inner IJ mirror type gas laser, the laser device of the present invention can be applied to any laser device that detects laser output with a solar cell and controls optical feedback.

Effects of the Invention As explained in detail above, the gas laser device of the present invention is not affected by the environmental temperature and has no effect on the temperature dependence of the solar cell for laser output detection. ! It is possible to perform stable feedback control of the gas laser device without being affected, and it is possible to stabilize the laser light output with a high degree of precision that has not been possible in the past.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of a gas laser device according to the present invention, and FIG. 2 is a graph showing temperature dependence of a solar cell.
The vertical axis represents the output signal level, and the horizontal axis represents the temperature. (Figure 3 is a circuit diagram showing an embodiment of the correction circuit provided in the optical feedback system of the laser device of Figure 1. [Main reference numbers] ■...Laser tube 2...Half mirror 3...Solar cell 4...Tori is circuit, 5...Laser oscillator 6...Laser power supply, 7 Correction circuit 8...Laser light Figure 2 Environmental humidity (0C)

Claims (1)

[Claims] The device includes a gas laser oscillator, a power source for driving the gas laser oscillator, and a solar cell that receives a portion of the output laser light from the gas laser oscillator, and the power source receives the output signal of the solar cell and operates the laser beam. In a gas laser device configured to control the discharge current of the gas laser oscillator so as to keep the light output constant, the gas laser device includes a temperature detecting means for detecting the temperature of the solar cell, and an output signal from the solar cell that detects the temperature of the solar cell. A gas laser device further comprising a correction circuit that performs correction based on the output of the detection means.