JPH0483387A - Laser apparatus - Google Patents

Abstract

PURPOSE:To obtain a maximum amplification factor by detecting an excitation timing and a trigger pulse phase in which laser power becomes maximum, and then controlling the phase to become the detected timing. CONSTITUTION:A delay amount Tdo from a basic pulse to a trigger pulse regulator 101b is set to a minimum value tmin to a gas laser amplifier 2a, and a detected value Te of an exciting timing detector 102b at this time, a power value p read from a laser power detector 103 and the amount Tdo are stored as Ter, P0, Tdr. Then, the delay amount is increased by Td, the power value P of the detector 103 is read, and compared with the power measured value P0 of the previous time. In the case of the read value P > the stored value P0, the stored excitation timing measured value Ter, the power value P0, and the delay mount Tdr are updated to the detected value Te of this time of the detector 102b, the power value P read from the detector 103 and a delay amount Tdo from a reference pulse. It is continuously executed until the delay amount reaches settable maximum value tmax.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a laser device, and particularly to a laser device that can always obtain maximum laser power.

[Prior art] Figure 3 shows a laser device, for example, JP-A-60-1448.
3 is a configuration diagram showing a conventional gas laser device disclosed in Publication No. 7, and in FIG. 3, (1) is a gas laser oscillator, (
2m) and (2b) are gas laser amplifiers that are installed in cascade behind the gas laser oscillator (1) and amplify the laser light; (3) is a mask pulse generator that outputs a reference pulse serving as an excitation command; (4a), (4b).

(4c) are connected to the mask pulse generator (3), and are connected to the gas laser generator (1) and the gas laser amplifier (2a), respectively.
), (2b).

Next, the operation will be explained. In the laser device, a power source (4a) is driven by a reference pulse from a mask pulse generator (3) to supply discharge energy to a gas laser oscillator (1) to excite it and output laser light. In addition, the power supply (4b) is driven by the reference pulse of the mask pulse generator (3), supplies discharge energy to the gas laser amplifier (2a), and excites it to amplify the output laser light of the gas laser oscillator (1). outputs a laser beam. Furthermore, the reference pulse of the mask pulse generator (3) causes the power supply (4c
) is driven to supply discharge energy to the gas laser amplifier (2b), excite it, and further output amplified laser light.

Each gas laser oscillator (1), gas laser amplifier <2i)
, (2b), respectively (4a), <4
b) and (4c) are constructed as shown in FIG. That is, the voltage of the DC power supply (10) is
) gas laser oscillation tube 2)
is applied to the electrode to generate a laser. The thyratron (11) is turned on and off by a pulse signal output from the pulse generator (13) that receives the reference pulse.

When the thyratron (11) is off, the charging/discharging capacitor (16) is in the charging phase, and as shown by the broken line arrow (19), the resonant charging reactor (14) is connected from the DC power source (10).
), a reverse blocking diode (15), a charging/discharging capacitor (16), and a charging circuit that returns to the DC power supply (10) via a charging/discharging resistor (20).
16) Charging is performed. When the thyratron (11) is on, it is the discharge period of the charge/discharge capacitor (16), and as shown by the solid arrow (17), the charge/discharge capacitor (16)
) is charged to the anode ( ) via the thyratron (11).
25), are applied to pulsed high voltage supply terminals (36^), (36K) which lead to the cathode (26), respectively. The pulse high voltage supply terminals (36^) and (36K) are connected to the outer tube (
32) as a conductive path to the anode (25) and cathode (26).

[Problem to be solved by the invention] Since the conventional laser device was configured as described above,
There has been a problem in that the excitation timing of the gas laser oscillator and gas laser amplifier shifts due to changes in the state of the gas in the gas laser oscillator tube, changes in temperature, changes in the characteristics of the power source including the thyratron, and the amplification of the laser beam decreases. .

This invention was made to solve the above-mentioned problems, and it is possible to obtain the maximum amplification by keeping the excitation timing constant regardless of changes in the temporal characteristics of the gas laser oscillation tube or power source. The purpose is to provide a laser device.

[Means for Solving the Problems] A laser device according to the present invention includes a gas laser oscillator that outputs laser light, and a plurality of gas laser amplifiers that amplify the laser light output from the gas laser oscillator. In the apparatus, means for detecting the excitation timing of each of the gas laser oscillator and the plurality of gas laser amplifiers, means for adjusting the phase of the trigger pulse of each of the gas laser oscillator and the plurality of gas laser amplifiers, and the a power detection means for detecting the power of the laser beam;
Sweeping the trigger pulse phase of the gas laser amplifier within a predetermined range, measuring the trigger pulse phase and excitation timing at which the laser power output from the power detection means is maximum, and thereafter matching the measured excitation timing. and control means for controlling the trigger pulse phase.

[Function] In the present invention, a control means for measuring excitation timing is provided, and first, the trigger pulse phase is swept to detect the excitation timing and trigger pulse phase at which the laser power becomes maximum, and thereafter, the above-mentioned detection The trigger pulse phase is controlled to achieve the desired excitation timing.

[Example] An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing one embodiment of the present invention, and (1
), (2a), (2b), (3), (
4a), <4b), and (4c) are completely the same as the above conventional device. In FIG. 1, (100) is an excitation timing control section, which controls the excitation timing signals of the excitation timing detection sections (102a), (102b), and (102e) and the power signal of the laser power detection section (103). The trigger pulse generation timing is calculated from , and the result is sent to the trigger pulse adjustment unit (Iotm) ~ (
101c). Trigger pulse adjustment section (101a
) to (101c) send trigger pulses to the power supplies (4a) to (4c) using the reference pulse from the mask pulse generator (3) at a phase corresponding to the command value from the excitation timing control unit (ioo).

The excitation timing detection units (102a) to (102c) detect excitation timing from the discharge current waveform. A laser power detection section (103) receives the laser light distributed from the optical system distributor (104) and detects the laser power.

Next, the operation will be explained with reference to FIG. First, the excitation operation of the laser will be explained using the gas laser oscillator (1) as an example.

The reference pulse from the mask pulse generator (3) is input to the trigger pulse adjustment section (101a), and the trigger pulse adjustment section (1 (lla)) outputs an amount proportional to the timing command signal from the excitation timing control section (100). The delayed pulse power source (4a) is supplied as an ON signal for the thyratron (11) (Fig. 4).The power source (4a) generates a trigger pulse for the trigger pulse adjustment section (101a) by the ON signal for the thyratron (11). The energy charged in the charge/discharge capacitor (16) (Fig. 4) is discharged to the gas laser oscillation tube (12) (Fig. 4) during the off period of the gas laser oscillation tube (12) (Fig. 4) to excite it. The discharge current (1)) to the oscillator tube (12) is detected by the current detector CT of the excitation timing detection section (102a), and the excitation timing calculation section TDET calculates the discharge current detected by the current detector CT from the reference pulse. (17) The time to the peak position is calculated and output to the excitation timing control section (100). Furthermore, the excitation operation of the gas laser amplifiers (2a) and (2b) is also controlled by the trigger pulse adjustment unit (101b) and (
101c), power supplies (4b), (4c), and trigger pulse adjustment units (101b), (101c), the operation is performed in exactly the same manner as the gas laser oscillator (1) described above.

Next, an excitation timing control method by the excitation timing control section (100) using the excitation operation described above will be explained.

The excitation timing control method includes an excitation timing calculation operation that detects the excitation timing at which the laser power reaches the maximum output, and an excitation timing constant control operation that is executed after the excitation timing calculation operation and maintains the excitation timing at which the laser power outputs the maximum output. Consisting of The excitation timing calculation operation to detect the excitation timing at which the laser power reaches its maximum output is performed using two gas laser amplifiers (2 m) and (2
This is the operation performed for b), and the following operation is performed first for the gas laser amplifier (2a) and then for the gas laser amplifier (2b).

First, for the gas laser amplifier (2a), the delay amount Tdo from the basic pulse is set to the minimum value Tl1l in the trigger pulse adjustment unit (101b), and the excitation timing detection unit (102b) detects the The value Te, the power value P read from the laser power detection unit (103), and the delay amount Tdo are stored as Ter, PO, and Tdr, respectively (
FIG. 2(a) Period I)L, Next, the delay amount is increased by ΔTd and the power value P of the laser power detection section (103)
Read and compare with the previous power measurement value PO. In the above comparison, when the read value P>the stored value PO, the stored excitation timing measurement value Ter, power value PO, and delay amount Td
r is updated with the current detection value Te of the excitation timing detector (102b), the power value P read from the laser power detector (103), and the delay amount Tdo from the reference pulse, respectively.

In the above comparison, if the stored value PO>reading value P, the above T
er, POlTdr is not updated and the process moves on to the next operation.

The next operation is to further increase the delay amount of the basic pulses by △Td, and compare the power read value P after increasing the delay amount of the basic pulses with the stored power value PO, as in the previous time.
In the comparison, when the read value P>the stored value PO, the excitation timing detection value Ter, the power value PO, and the delay amount Tdr which are stored are sent to the excitation timing detection unit (102b).
) current detected value Te, laser power detection unit (103)
Read power value P, delay amount Td from reference pulse
Update with o. In the above comparison, when the stored value PO>jR value P, the excitation timing detection value is not replaced (period ■ in FIG. 2(a)).

The above operations are performed continuously until the delay amount of the basic pulse reaches the maximum value t□yo that can be set. (Figure 2 (a) Period ■).

As a result of the above operation, the stored excitation timing detection value Te
r and the delay amount Tdr from the reference pulse are used as control reference values for constant excitation timing control.

The gas laser amplifier (2b) is operated in exactly the same way as the gas laser amplifier (2a) using an excitation timing detection section (102e), a laser power detection section (103), and a trigger pulse adjustment section (101c). Obtain control reference values Ter and Tdr for constant excitation timing control operation.

For the gas laser oscillator (1), an intermediate value t, 1. The detected value of the excitation timing detector (102a) at this time is set as the control reference value Te.
Let r, tml be the control reference value Tdr, and immediately proceed to the excitation timing constant control operation shown later.

The excitation timing constant control operation that maintains the maximum laser power (Fig. 2 (b)) is performed by the gas laser oscillator (1).
, gas laser amplifiers (2a), and (2b) as follows.

For the gas laser oscillator (1), the deviation ΔTe between the detection value Te of the excitation timing detection unit (102g) and the control reference value Ter held by the excitation timing calculation operation is calculated using the formula (1), and the above-mentioned ΔTe = Ter-Te
(1) Perform the calculation shown in equation (2) on the control reference value Tdr of the delay amount from the reference pulse whose deviation is maintained by the excitation timing calculation operation, and use the result as the new command value Tdr of the delay amount.
The trigger pulse Tdo = Tdr + ΔTe (2) is output to the adjustment section (101a) as o. In other words, the amount of change in excitation timing is compensated for by the amount of delay from the reference pulse.

Following the above equation (2), the calculation of equation (3) is performed.

Tdr = Tdo
(3) Because, due to the operation of equations (1) and (2) above, △
Since Te=0 is compensated, unless there is further drift in the excitation operation after the next cycle, it is necessary to continue outputting the result of the above equation (2) as the delay amount, and this is achieved by the operation of this equation (3). can.

The excitation timing constant control operation for the gas laser amplifier (2a) is achieved by using the trigger pulse adjustment section (101b) and the excitation timing detection section (102b), and by the same operation as the gas laser oscillator (1) described above.

Furthermore, the excitation timing constant control operation for the gas laser amplifier (2b) is performed by a trigger pulse adjustment section (101c).
This is realized by using the excitation timing detection section (102c) and the same operation as the gas laser oscillator (1) described above.

In the excitation timing constant control operation described above, the gas laser oscillator (1), the gas laser amplifier (2a), (2b
) can accurately correct the amount of change in excitation timing due to drift by the amount of delay from the reference pulse, so the gas laser oscillator (1) and gas laser Amplifier (2
a) and (2b) continue to be excited, respectively.

[Effects of the Invention] As described above, according to the present invention, there is provided a laser device including a gas laser oscillator that outputs laser light and a plurality of gas laser amplifiers that amplify the laser light output from the gas laser oscillator. means for detecting the excitation timing of each of the gas laser oscillator and the plurality of gas laser amplifiers; and means for adjusting the phase of the trigger pulse of each of the laser oscillator and the plurality of gas laser amplifiers;
power detection means for detecting the power of the gas laser beam; and trigger pulse phase and excitation timing for sweeping the trigger pulse phase of the gas laser amplifier within a predetermined range to maximize the laser power output from the power detection means. Since it is equipped with a control means that measures the trigger pulse phase and thereafter controls the trigger pulse phase to match the measured excitation timing, it is possible to prevent changes in the state of the gas in the gas laser oscillation tube, changes in temperature, changes in the characteristics of the power source including the thyratron, etc. Therefore, even if the excitation timing of the gas laser oscillator and the gas laser amplifier deviates, the excitation timing can be controlled to be optimal, so that the maximum laser power that the laser device can produce is always obtained.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram showing an embodiment of a laser device according to the present invention, FIG. 2 is a timing diagram for explaining the invention in detail, FIG. 3 is a configuration diagram showing a conventional laser device, and FIG.
The figure is a configuration diagram showing details of the power supply section. In the figure, (1) is a gas laser oscillator, and (2a) is a gas laser oscillator. (2b) is a gas laser amplifier, (3) is a mask pulse generator, (4a), (4b), (4a) are power supplies,
(100) is an excitation timing control unit, <Iota),
(101b), (101c) are trigger pulse adjustment units, (102a), (102b), (102c)
) is an excitation timing detection section, and (103) is a laser power detection section6. Note that the same reference numerals in each figure indicate the same or corresponding parts.

Claims (1)

[Scope of Claims] A laser device comprising a gas laser oscillator that outputs laser light, and a plurality of gas laser amplifiers that amplify the laser light output from the gas laser oscillator, wherein the gas laser oscillator and the plurality of gas laser oscillators means for detecting the excitation timing of each of the gas laser amplifiers; means for adjusting the phase of the trigger pulse of each of the gas laser oscillator and the plurality of gas laser amplifiers; and power detection means for detecting the power of the laser beam. , Sweeping the trigger pulse phase of the gas laser amplifier within a predetermined range, measuring the trigger pulse phase and excitation timing at which the laser power output from the power detection means is maximum, and thereafter matching the excitation timing with the measured excitation timing. 1. A laser device comprising: control means for controlling a trigger pulse phase so as to control a trigger pulse phase.