JPH05335675A - Laser device - Google Patents

Abstract

PURPOSE:To always obtain the maximum laser light output from a laser device by providing a means which controls the exciting timing of the laser device. CONSTITUTION:By calculating the generating timing of a trigger pulse 50 from the power signal 102a of a laser power detecting section which receives the laser light component 5a of the output laser light 5 distributed from an optical- system distributor 103, the calculated results are outputted to trigger pulse adjusting sections 101a, 101b, and 101c as command values phia, phib, and phic. Namely, each trigger pulse adjusting section 101a, 101b, and 101c is constituted so that each section can send a reference pulse 3a from a master pulse generator 3 to each power source 4a, 4b, and 4c at phases corresponding to the command values phia, phib, and phic from an exciting timing control section 100. Therefore, the section 100 is constituted so that each gas laser amplifier 2a and 2b can be alternately controlled in the direction in which the output laser light 5 increases and, at the same time, the phase of the trigger pulse 50 can be controlled.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser device,
In particular, the present invention relates to a configuration that compensates for a decrease in output laser power due to drift.

[0002]

2. Description of the Related Art FIG.
FIG. 6 is a block diagram showing a conventional gas-type laser device disclosed in Japanese Patent Publication No. 62-14487, which includes two gas laser amplifiers 2 a, 2 a connected to a gas laser oscillator 1.
2b, a master pulse generator 3 for outputting a reference pulse 3a as an excitation command, a power source 4 for supplying the discharge energy of the gas laser generator 1 and the gas laser amplifiers 2a, 2b.
It is composed of a, 4b and 4c.

In the laser device thus constructed, the first power source 4a is driven by the reference pulse 3a of the master pulse generator 3.
Supplies discharge energy to the gas laser oscillator 1 to excite it, and outputs laser light. Further, the second power source 4b supplies discharge energy to the first gas laser amplifier 2a to excite it by the reference pulse 3a of the master pulse generator 3, and outputs a laser beam obtained by amplifying the laser beam 1a of the gas laser oscillator 1. .. Furthermore, the third power supply 4c supplies discharge energy to the second gas laser amplifier 2b by the reference pulse 3a of the master pulse generator 3 to excite it, and further outputs the amplified output laser light 5.

Power supplies 4a, 4b and 4c for exciting the gas laser oscillators 1 and the gas laser amplifiers 2a and 2b.
Is configured as shown in FIG. That is, the DC power source 1
A voltage of 0 is applied to the electrode of the gas laser oscillation tube 12 by the on / off operation of the thyratron 11 to generate a laser. This thyratron 11 has a pulse signal 1 output from a pulse generator 13 which receives the above-mentioned reference pulse 3a.
3a turns on and off. When the thyratron 11 is off, the charging / discharging capacitor 16 is in the charging period, and as shown by the broken line arrow 19, the resonance charging reactor 14, the reverse current blocking diode 15, the charging / discharging capacitor 16 and the charging / discharging capacitor 16 are connected from the DC power supply 10. DC power supply 1 via resistor 20
The charging / discharging capacitor 16 is charged by the loop-shaped charging circuit returning to zero.

When the thyratron 11 is on, the charging / discharging capacitor 16 is in a discharging period, and the charging voltage of the charging / discharging capacitor 16 is passed through the thyratron 11 to the anode 25 of the laser oscillation tube 12 as shown by a solid arrow 17. And pulse high voltage supply terminals 36A, 3 connected to the cathode 26
Applied at 6K. This pulse high voltage supply terminal 36A,
36K is connected to the anode 25 and the cathode 26 by using the outer tube 32 of the laser oscillation tube 12 as a conductive path.

[0006]

The conventional laser device is
Since it is configured as described above, there are the following problems. That is, in the conventional example, the pumping timing of the gas laser oscillator and each gas laser amplifier connected in series is shifted due to the gas state change of the gas laser oscillation tube, the temperature change, the characteristic change of the power supply including the thyratron, and the like. However, there was a serious problem that the output of was decreasing.

The present invention has been made to solve the above problems, and in particular, always obtains the maximum laser light output regardless of changes in the characteristics over time of the gas laser oscillator tube and the power supply. It is an object of the present invention to provide a laser device capable of performing the above.

[0008]

A laser device according to the present invention comprises a laser power detector for detecting the output laser power of an output laser obtained from a gas laser amplifier, the gas laser oscillator and a plurality of gas laser amplifiers. A trigger pulse adjusting unit for adjusting the phase of each trigger pulse, and an excitation timing control unit for receiving a power signal from the laser power detecting unit and outputting a command value to each trigger pulse adjusting unit are provided. It is a composition.

[0009]

In the laser device according to the present invention, the laser power detecting means is provided, the power signal from the detecting means is input to the timing control section, and the trigger pulse phase supplied to each gas laser amplifier is adjusted. , A plurality of gas laser amplifiers are alternately controlled so that the output laser light is amplified. Therefore, the maximum laser that the laser device can output is always irrespective of fluctuations in the pumping timing of the gas laser oscillator and the gas laser amplifier due to changes in the gas state of the gas laser oscillator tube, changes in the temperature, changes in the characteristics of the power supply including the thyratron, etc. You can get power.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the laser device according to the present invention will be described in detail below with reference to the drawings. In FIG. 1, 1 is a gas laser oscillator that generates a laser beam 1a, 2
a and 2b are first and second gas laser amplifiers, 4a and 4b,
Reference numeral 4c denotes a first gas laser oscillator 1, a first gas laser amplifier 2a, and a first gas laser amplifier 2b connected to the first gas laser amplifier 2a.
The second and third power supplies. Reference numeral 100 denotes an excitation timing control unit, which is a laser power detection unit 10 that receives the laser light 5a of the output laser light 5 distributed from the optical system distributor 103.
Calculating the generation timing of the trigger pulse 50 from the second power signal 102a, the result command value φ _a, φ _b, each trigger pulse adjustment unit 101a as φ _c, 101b, 101
Output to c. That is, each of these trigger pulse adjusting units 101a, 101b, 101c applies the reference pulse 3a from the master pulse generator 3 to the excitation timing control unit 1.
The command value from 00 φ _a, φ _b, the power supply 4a in phase corresponding to phi _c, 4b, and is configured to deliver said trigger pulse 50 to 4c. Therefore, the excitation timing control unit 100 is configured to alternately control the gas laser amplifiers 2a and 2b in the direction in which the output laser beam 5 increases and the phase of the trigger pulse 50.

The laser device according to the present invention is configured as described above, and its operation will be described below. First, FIG. 2 shows a control program installed in the excitation timing control unit 100 of FIG. 1 according to the present invention. First, in the first block 200, the excitation timing of the gas laser oscillator is controlled to maximize the output of the output laser light 5. Next, in the second block 300, the pumping timing of the first gas laser amplifier 2a is controlled so that the output laser beam 5
Output is maximum. Further, the third block 400 controls the pumping timing of the second gas laser amplifier 2b,
The output of the output laser light 5 is maximized. Then, again to control the excitation timing of the gas laser oscillator 1, the first
Returning to block 200, the above operation is repeated thereafter.

The gas laser oscillator 1 and the respective gas laser amplifiers 2a and 2b of the blocks 200, 300 and 400 described above.
The excitation timing control method is the same, and the following procedure is performed. First, the following items are sequentially executed as an initial setting. In the first step 201, the output laser power P of the output laser 5 is read. In the second step 202, the excitation timing phase is controlled to the delay side. Third step 203
Then, the delay control command is turned on, and the fact that the delay side is controlled is stored. In the fourth step 204, the stored value of the control direction change count is set to "0". After the initial setting is completed, the output laser beam 5 is controlled to be the maximum by the following procedure. In the fifth step 205, the output laser power P read before the above control is stored as P ′. (Note that the value read in the first step 201 after completion of the initial setting and the value read in the sixth step 206 after the start of control are P ′.) In the sixth step 206, the output laser power P Read. In the seventh step 207, it is judged by the delay control command whether or not the delay side control is performed.

If it is determined in this determination that the delay side has been controlled, the process branches to the eighth step 208 and control is performed according to the changing direction of the output laser beam 5. The eighth step 2
The change judgment of the output laser beam 5 at 08 is in the increasing direction (P-
When P ′> 0), the excitation timing is further controlled to the delay side in the ninth step 209. The eighth step 208
The change judgment of the output laser light in the decreasing direction (P-P '<
When it is 0), the process branches to the tenth step 210, and conversely to the above, the excitation timing is controlled to the advanced side. In the tenth step 210, the stored value of the control direction change count is incremented by one. The number of changes in the control direction is the eleventh step 211.
It is judged by. If it is determined in the 11th step 211 that the number of changes in the control direction is 2, it means that the pump timing has already been controlled to the delay side and the advance side and the output laser beam 5 has reached the maximum pump timing. Therefore, the control is completed and the control of the next block is performed.

Here, the reason why the maximum output laser light is obtained by controlling the pumping timing to the delay side and the advance side is due to the characteristics of the gas laser amplifiers 2a and 2b shown in FIG. That is, the amplification degree of each of the gas laser amplifiers 2a and 2b is maximized at a specific pumping timing φ ₀ , and the amplification degree is decreased on the delay side or the advance side of the pumping timing φ ₀ . Therefore, the maximum output laser light can be obtained by sweeping in both the delay side and the advance side and determining the pumping timing at which the output laser power P of the output laser 5 starts to decrease.

Next, if it is judged in the judgment of the 11th step 211 that the number of control direction changes is not 2, the first judgment is made.
The process proceeds to step 212 and the excitation timing is controlled to the advanced side. Then, in the thirteenth step 213, the delay control command is turned off, and the fact that the excitation timing is controlled to the advanced side is stored.

In the judgment of the seventh step 207,
If it is determined that the control is performed to the leading side (delay control command is turned off), the process branches to the fourteenth step 214, and control is performed according to the changing direction of the output laser light. The change judgment of the output laser beam 5 in the fourteenth step 214 is in the increasing direction (PP ′>
When it is 0), the excitation timing is further controlled to the advanced side in the fifteenth step 215. The change judgment of the output laser light 5 in the fourteenth step 214 is in the decreasing direction (PP ′ <
When it is 0), the process branches to the 16th step 216, and conversely to the above, the excitation timing is controlled to the delay side. This 16th
In step 216, the stored value of the control direction change count is set to +1.
To do. The number of times the control direction is changed is calculated in the seventeenth step 21.
It is judged at 7.

When it is determined in the 17th step 217 that the number of changes in the control direction is 2, the excitation timing has already been controlled to the delay side and the advance side and the output laser light reaches the maximum excitation timing. As a result, the control is completed and the control of the next second block 300 is started. If it is determined in the 17th step 217 that the number of changes in the control direction is not 2, the process proceeds to an 18th step 218, and the excitation timing is controlled to the delay side. And the first
In step 219, the delay control command is turned on, and the fact that the excitation timing is controlled to the delay side is stored.

FIG. 3 shows a specific control example of the operation of the laser device of the present invention described above. That is,
In FIG. 3, periods I and IV are control periods of the gas laser oscillator 1, period II is a control period of the first gas laser amplifier 2a, and period III is a control period of the second gas laser amplifier 2b. In the period I, the excitation timing of the gas laser oscillator 1 is first controlled on the delay side. In this case the output laser beam 5 increases until shortly before the time t _11, since decreased in time t _11, the excitation timing advanced side is controlled. In this case the output laser beam 5 increases until shortly before the time t _12, the time t ₁₂
However, since the excitation timing tries to control the excitation timing further to the delay side, the number of changes in the control direction is the second time,
The control of the excitation timing of the gas laser oscillator 1 is completed since the maximum excitation timing of the output laser light was obtained.

In period II, the first gas laser amplifier 2
First, the excitation timing of a is controlled on the delay side. At this time, since the output laser light 5 has decreased, the excitation timing is controlled to the advancing side at time t ₂₁ . Then the output laser beam 5 increases until shortly before the time t _22, since decreased in time t _11, tries to control the further delayed side excitation timing, the number of changes in the control direction is the second time, the output laser beam Since the maximum pumping timing of 5 has been obtained, the control of the pumping timing of the first gas laser amplifier 2a is completed.

In the period III, the pumping timing of the second gas laser amplifier 2b is first controlled to the delay side. In this case the output laser beam 5 increases until shortly before the time t _31, since decreased in time t _31, the excitation timing advanced side is controlled. Because the output laser beam 5 this time increases until shortly before the time t _32, was reduced with time t _32, tries to control the further delayed side excitation timing, the number of changes in the control direction is the second time, the output laser beam Since the maximum pumping timing of 5 has been obtained, the control of the pumping timing of the second gas laser amplifier 2b is completed.

As described above, the excitation timings of the gas laser oscillator 1 and the respective gas laser amplifiers 2a and 2b are swept to the delay side and the advance side to obtain the maximum excitation timing of the output laser beam 5, and a plurality of gas lasers are obtained. Amplifiers 2a, 2
Alternately control b. In this embodiment, the laser amplifiers 2a and 2b have a two-stage configuration, but the number is not limited to two, and a multi-stage configuration is also possible.

[0022]

As described above, according to the present invention, the output laser power detecting means of the laser device is provided, and the means for controlling the excitation timing so that the output laser light is maximized is provided. Therefore, the gas laser oscillation tube is provided. The effect that the maximum laser power that can be output by the laser device can always be obtained regardless of changes in the excitation timing of the gas laser oscillator and gas laser amplifier due to changes in the gas state, changes in temperature, changes in the characteristics of the power supply including the thyratron, etc. is there. Further, according to the present invention, the pumping timing of a plurality of gas laser amplifiers can be performed without interference, so that the present invention can be easily applied regardless of the number of gas laser amplifiers. Furthermore, it is only necessary to detect the laser light at the final stage, and it is not necessary to detect the laser light of each gas laser amplifier, and there is no unnecessary loss of laser light due to the arrangement of the optical system distributor, and there is no loss of efficiency. Highly efficient control is obtained.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a laser device according to the present invention.

FIG. 2 is a flowchart showing the operation of the laser device according to the present invention.

FIG. 3 is a timing diagram showing the operation of the laser device according to the present invention.

FIG. 4 is a characteristic diagram showing excitation timing in the present invention.

FIG. 5 is a configuration diagram showing a conventional laser device.

FIG. 6 is a detailed configuration diagram showing a main part of FIG.

[Explanation of symbols]

 1 Gas Laser Oscillator 1a Laser Light 2a, 2b Gas Laser Amplifier 5 Output Laser Light 100 Excitation Timing Control Section 101a, 101b, 101c Trigger Pulse Adjusting Section 102 Laser Power Detection Section 102a Power Signal

Claims (1)

[Claims] 1. A laser device comprising a plurality of gas laser amplifiers for amplifying laser light output from a gas laser oscillator for outputting laser light, wherein output laser power of an output laser obtained from the gas laser amplifier is detected. A laser power detection unit, a trigger pulse adjustment unit for adjusting the phase of each trigger pulse of the gas laser oscillator and the plurality of gas laser amplifiers, and each trigger pulse that receives a power signal from the laser power detection unit A pumping timing control unit for outputting a command value to the adjustment unit, the pumping timing control unit, the phase of the trigger pulse in the direction in which the gas laser amplifiers alternately and the output laser light increases. A laser device characterized by being controlled.