JPH0715070A - Timing control device - Google Patents

Abstract

(57) [Summary] [Object] An object of the present invention is to set an appropriate timing time while controlling an indefinite time and control the oscillation timing of each laser oscillator. [Configuration] A plurality of laser oscillators L ₁ , L ₂ , ... Are arranged in series and in multiple stages, and each of the laser oscillators is controlled to oscillate at an optimal oscillation timing time from delay units 12 ₁ , 12 ₂ , ... Corresponding to these laser oscillators. In the timing control device of the laser device, for each delay unit, in addition to the constant delay time Ti depending on the speed of light, etc., it is obtained from the delay function that represents the delay time that changes until the stable region is reached after the laser device starts operating. A first time setting means 11 for setting an indefinite delay time ti and a timing time determining means 12 for determining an oscillation timing time from the constant delay time Ti and the indefinite delay time ti are provided, and the oscillation timing time (Ti -Ti) is used to control each laser oscillator.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is an improvement of a timing control device for controlling the oscillation timing of each laser oscillator in order to obtain a large output laser beam by sequentially amplifying the laser beam by using laser oscillators arranged in multiple stages in series. Regarding

[0002]

2. Description of the Related Art Generally, a high-power laser device of this type has a plurality of laser oscillators, such as L, as shown in FIG.
A structure in which _{1 to} L ₄ are arranged in series is used. These pumps laser oscillators, such as copper vapor laser oscillating output at the timing of the required amplified laser light is used for the laser oscillator L ₁ ~L _4.

However, in such a high-power laser device, when the oscillation timing time of the laser oscillator L ₁ is T ₁ , as is apparent from the figure, the oscillators L ₂ , L ₃ , L
The optimum oscillation timing times for ₄ are (T ₁ +
T ₂ ), (T ₁ + T ₂ + T ₃ ), (T ₁ + T ₂ + T ₃ +
It is represented by T ₄ ). In addition, this time T ₁ , T ₂ , T ₃ ,
T ₄ means the delay time of the oscillation timing of each oscillator L ₁ , L ₂ , L ₃ , L ₄ , which is the time required for light to pass the distances D ₁ , D ₂ , D ₃ , respectively. .
Now, if the speed of light is C, the light is at each distance D ₁ ,
The time required to pass through D ₂ and D ₃ is represented by T ₂ = D ₁ / C, T ₃ = D ₂ / C, and T ₄ = D ₃ / C. Note that this time is on the order of several nsec to ten and several nsec.

By the way, the timing control device applied to the high-power laser device as described above usually receives one clock signal and delays it by a time required by each delay unit in consideration of the above time relationship. taking a method of controlling the laser output of each oscillator _{L 1, L 2, L 3} , L 4 while.

FIG. 9 is a diagram showing the structure of such a timing control device. This device includes, for example, a delay unit 2 ₁ , 2 corresponding to each laser oscillator in advance from a computer 1.
_The oscillation timing times T ₁ , (T ₁ + T ₂ ), (T ₁ + T) based on the delay times T ₁ , T ₂ , T ₃ , T ₄ due to the speed of light described above with respect to ₂ , 2, ₃ and 2 _{4. 2} + T ₃ ),
Set (T ₁ + T ₂ + T ₃ + T ₄ ).

Thereafter, for example, when a laser device operation start command is issued from the computer 1, the master clock generation source 3 is generated in each of the delay units 2 ₁ , 2 ₂ , 2 ₃ and 2 _4.
When the preset oscillation timing times T ₁ , (T ₁ + T ₂ ), ... Are reached while counting the master clock generated from the laser oscillators, the thyratrons 4 ₁ , 4 serving as power sources of the laser oscillators L ₁ , L ₂ ,. ₂ , send drive signal to. Wherein each thyratron 4 _1, 4 _2, ... generates a large current pulse begins discharging (see FIG. 8), a car rent probe 5 _1, 5 _2, the laser oscillator L ₁ corresponding through ...,
It is applied as a trigger signal to L ₂ ,. In this case, each car rent probe 5 _1, 5 _2, ..., each thyratron 4 _1, 4 _2, while measuring ... output current value of each thyratron 4 _1, 4 _2, set the output current value of ... in advance It is detected whether or not the optimum set value has been exceeded, and this detection signal is sent to the high-speed stopwatch circuit 6. This high-speed stopwatch circuit 6 is provided with each current probe 5 ₁ , 5 ₂ , ...
The actual oscillation time is measured by the
Control is performed by feeding back to ₁ , 2 ₂ , ... to correct the delay time.

[0007]

However, in the above-mentioned large-scale laser device, the following problems have been pointed out in controlling the oscillation timing.

(1) One of them is the existence of a delay element that prevents the optimum oscillation timing time. This delay element includes discharge delay time of the thyratron itself, driver pulse delay due to temperature drift, and laser oscillators L ₁ and L.
₂ , the discharge delay time in etc. can be increased. It can be said that these delay times are indefinite values, while the delay due to the speed of light is a relatively constant value. So, below,
This indefinite value is called "indefinite delay time". This indefinite delay time is the delay time T of the oscillation timing described above.
It becomes an element that delays ₁ , T ₂ , T ₃ , and T ₄ further.

Moreover, this indefinite delay time drops sharply immediately after the laser device starts operating, as shown in FIG.
Then, after a certain time elapses, a substantially constant time delay t
_It has the property of settling at ₀ . This requires some kind of warm-up until the delay time stabilizes. Although FIG. 10 shows the system as a dead time + temporary delay system, this change mode cannot always be specified.

FIG. 11 is a diagram for explaining timing control in consideration of such an indefinite delay time. That is, the timing control, delay units 2 _1, 2 _2, previously undefined delay time from ... t _1, t _2, and outputs a signal ... in a state of minute only ahead, thyratron 4 _1, 4 _2, optimal from ... The current waveform is output at the oscillation timing times T ₁ , T ₁ + T ₂ , ...

Therefore, if the control is performed at the optimum oscillation timing time which is set in advance in consideration of the indefinite delay times t ₁ , t ₂ , ... In the initial stage, the variation due to the machine difference of each laser oscillator system is small, so that it is almost the same. If there is a uniform deviation, by performing processing such as zero shift,
It is possible to secure sufficient stability.

However, as described above, since the indefinite delay times t ₁ , t ₂ , ... Are constants that change with time, the optimum oscillation is first considered while considering the indefinite delay times t ₁ , t ₂ ,. Even if the timing time is set, it changes with the passage of time and has a great influence on accuracy and stability.

Each of the laser oscillators L ₁ , L ₂ , ... Has a life and needs to be sequentially replaced after an appropriate period. By the way, the most advanced US CVL
Therefore, the target life is considered to be 5000 hours. Therefore, for example, when a chain is composed of 10 laser oscillators, the replacement work is required 20 times a year. Since the laser oscillator after the replacement has an indefinite time delay different from that of the existing one, the stability of control is impaired each time the laser oscillator is replaced.

(2) Further, after the laser oscillator is replaced as described above, the optimum oscillation timing times T ₁ , T ₁ + T ₂ , ... Which should be set in advance before and after the replacement are changed. Time, trial run time is required,
There is a problem of being forced to suspend. (3) Another problem is that the speed of light changes according to changes in temperature and atmospheric density, affecting the optimum oscillation timing time.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a timing control device for controlling an oscillation timing of each laser oscillator by setting an appropriate timing time while considering an indefinite time. .

[0016]

First, in order to solve the above-mentioned problems, the invention according to claim 1 has a configuration in which a plurality of laser oscillators are arranged in series and in multiple stages, and a delay unit corresponding to these laser oscillators is most suitable. In the timing control device of the laser device that controls the oscillation of the corresponding laser oscillator with the oscillation timing time,

For each of the delay units, in addition to a constant delay time depending on the speed of light or the like, an indefinite delay time obtained from a delay function that represents a delay time that changes until the stable region is reached after the laser device starts operating. The configuration is such that first time setting means for setting and timing time determining means for determining an oscillation timing time from the constant delay time and the indefinite delay time are provided in each of the delay units.

Next, the invention according to claim 2 corresponds to the exchanged laser oscillator when the arbitrary laser oscillator is exchanged after the stable delay time has been reached due to the passage of time after the start of operation of the laser device. The delay unit is set to an indefinite delay time obtained from a delay function that expresses a delay time that changes until the stable region is reached after the laser device starts operating, while corresponding to a laser oscillator in a non-exchange state. A second time setting means for setting the stable delay time is provided for the delay unit.

Further, the invention according to claim 3 corresponds to the arbitrary laser oscillator in addition to the means for taking out the feedback correction time from the difference between the actual oscillation time of the arbitrary laser oscillator and the preset time. With respect to the delay unit, in addition to a constant delay time depending on the speed of light, an indefinite delay time and a feedback correction time obtained from a delay function that represents a delay time that changes until a stable region is reached after the laser device starts operating. The third time setting means for setting is set.

Further, the invention according to claim 4 is arranged such that a plurality of mirrors are bypassed on the input / output side of a laser oscillator to be replaced among a plurality of laser oscillators, and the bypass line is supplemented. The laser oscillator is arranged and the arbitrary laser oscillator is replaced while continuing the operation of the laser oscillator.

[0021]

Therefore, in the invention corresponding to claim 1, by taking the above-mentioned means, the first time setting means for each delay unit causes a constant delay time due to the speed of light or the like and a laser device. Since the change of the delay time until the stable region is reached after the start of the operation is made into a function, and the indefinite delay time is set stepwise based on this function, the timing time determining means of each delay unit depends on the speed of the light or the like. Since the power supply for driving the laser oscillator is controlled at the time obtained by subtracting the indefinite delay time from the constant delay time, the optimum timing can be achieved without performing feedback control as in the past and requiring special calculation by the computer. Laser light can be output at the time.

Next, in the invention according to claim 2, the indefinite delay time is stabilized after a certain period of time has passed after the start of operation of the laser device, but it is necessary to replace it due to the life of the laser oscillator or the like. Only for the delay unit corresponding to this laser oscillator after replacement, set the indefinite delay time obtained by using the function of the delay time that changes until the stable region is reached after the start of operation, and set the oscillation timing more than other laser oscillators. Since the time is set earlier, the laser light can be output at the optimum timing with certainty even if the laser oscillator after replacement and the non-replacement laser oscillator are mixed, and there is no need to perform feedback control as described above. Also, the capacity of the computer can be significantly reduced.

Further, the invention according to claim 3 incorporates not only an indefinite delay time in consideration of the operation period of the laser device but also feedback control similar to the conventional one, so that the laser oscillator can be replaced at a non-steady time. , It is possible to oscillate a laser beam with extremely high efficiency and stability regardless of the steady state.

Further, in the invention according to claim 4, the mirror is bypassed on the input / output side of the laser oscillator to be exchanged, and the auxiliary laser oscillator is arranged in this bypass line to continuously provide laser light. Can be oscillated.

[0025]

BEST MODE FOR CARRYING OUT THE INVENTION The apparatus of the present invention is to drive not only a constant delay time due to the speed of light but also an indefinite delay time with respect to the operation timing of, for example, a thyratron which is a power source for controlling each laser oscillator. . As shown in FIG. 10, this indefinite delay time changes in a substantially constant pattern after the laser device starts operating and becomes stable, and it is noted that the indefinite delay time stabilizes to a constant value after a certain time has elapsed, and various timings are considered. It is to realize the control device.

A first embodiment of the device of the present invention will be described below with reference to FIGS. 1 and 2. Since this device has almost the same configuration as the conventional device, the same parts are designated by the same reference numerals.

The device of the present invention is different from the conventional device in that the delay time T ₁ , T ₂ from the computer 11 as the first time setting means to each delay unit 12 ₁ , 12 ₂ , ... , ... In addition to the start of operation of the laser device until the operation is stabilized, a functional expression as shown in FIG. 2, that is, −t _i (i = 1, 2, ...) = fx (t)

Each delay unit 12 ₁ , 1 is used as a delay function equation and is regarded as a stepwise constant change.
2 _2, sequentially indefinite delay time ... to t _1, t _2, set the ...,
In addition, a constant delay time t ₀ is set in consideration of the fact that the period has elapsed and stable operation has been reached.

Therefore, the delay units 12 ₁ and 1
In 2 ₂ , ..., Oscillation timing delay times T ₁ , T ₂ ,
Using the oscillation timing times obtained by subtracting the indefinite delay times t ₁ , t ₂ , ... From each thyratron 4 ₁ , 4
₂ , ... drive. As a result, the thyratron 4 ₁ , 4
₂ , ... Starts discharge and outputs a large current pulse. Each laser oscillator L ₁ , L ₂ , ... Is a thyratron 4 ₁ , 4 ₂ ,
Receiving a trigger signal of a large current pulse from ..., it oscillates and outputs the amplified laser light.

Therefore, according to the configuration of the above-described embodiment, the computer 11 sets the timing data in the delay units 12 ₁ , 12 ₂ , ... Since a high-speed stopwatch circuit 6 and an arithmetic circuit by a computer are unnecessary, extremely simple timing control can be realized. Moreover, each laser oscillator L ₁ , L
Since it is possible to easily compensate for the indefinite delay time of the oscillation timing when replacing ₂ , ..., A stable laser oscillation state can be obtained.

Next, a second embodiment of the device of the present invention will be described with reference to FIG. This embodiment is a diagram showing an example of timing control when one laser oscillator, for example, L ₂ is replaced at the time of stable operation.

Specifically, each laser oscillator L ₁ ,
Assuming that the distances between the devices L ₂ , L ₃ and L ₄ are equal and the machine difference in delay time after operation stabilization is small, the indefinite delay time and the delay time of the oscillation timing are t ₁ = t ₂ = T ₃ = t ₄ = t ₀ T ₁ = T ₂ = T ₃ = T ₄ Therefore, when the operation is stable, T ₁ −t ₀ , 2T ₁ −t ₀ , 3T ₁ −t ₀ , 4T ₁ −t are output from the delay units 2 ₁ , 2 ₂ , 2 ₃ , 2 _4.
0

The laser oscillator L ₁ by using a composed oscillation timing time, L _2, L _3, is to control the L _4, the exchange initial time of the laser oscillator L ₂ as described above, the laser oscillator L ₂ is a non-stable state Since it is in the (unsteady state), T ₁ −t ₀ , 2T ₁ −f (t), 3T ₁ −t ₀ , 4T _{1 are} output from the delay units 2 ₁ , 2 ₂ , 2 ₃ , 2 _4.
-T ₀

The thyratron 4 ₁ , 4 ₂ , 4 ₃ , 4 ₄ is driven by using the oscillation timing time, and a trigger signal is given to the laser oscillators L ₁ , L ₂ , L ₃ , L ₄ . That is, when replacing the laser oscillator L _2, compared to only a the power exchanged laser oscillator L ₂ thyratron 4 ₂ delay time to other timed to advance only [f (t) -t _0] , Other delay times are uniformly multiples of T ₁ -t
_The timing should be ₀ . Since these time delays can be treated as fixed values, the delay units 2 ₁ , 2 ₂ , 2 ₃ , 2 ₄ can deal with them.

Therefore, according to the configuration of this embodiment, it is sufficient to divide the time into the non-steady state and the steady state, and set the predetermined delay time t ₀ in the non-exchange period based on the delay function in the non-steady state such as exchange. The capacity of 11 can be reduced, and the number of data input / output processing units can be significantly reduced.

Next, a third embodiment of the device of the present invention will be described with reference to FIG. In this embodiment, a high-speed stopwatch circuit 13 is provided as in the conventional device, and the actual oscillation time measured by the current probe 5 ₁ , 5 ₂ , ... In the high-speed stopwatch circuit 13 and a preset set time are set. Are compared and the time difference, that is, the feedback correction time Δti (i = 1, 2, ...) Is transmitted to the bus line.

[0037] In this case, the computer 11, after incorporating feedback correction time △ ti from the bus line, the feedback correction time to the indefinite delay time t ₁ ~t ₄ △ ti
The value obtained by adding is set to each delay unit 2 ₁ , 2 ₂ , .... Then, the thyratrons 4 ₁ , 4 ₂ , ... Are driven by using the oscillation timing times set by the computer 11 in the delay units 2 ₁ , 2 ₂ ,.

According to this embodiment, although the cost is slightly higher, the feedback correction time Δti is individually obtained by the high-speed stopwatch circuit 13, so that the laser oscillator can be exchanged at a non-steady state or at a steady state. A stable laser beam can be obtained very efficiently.

Further, a fourth embodiment of the device of the present invention will be described with reference to FIG. This example is a diagram showing a modified example of the second embodiment, a car rent probe 5 ₂ specifically corresponds to the laser oscillator L ₂ that was exchanged
Captures the feedback correction time △ ti from the delay unit 2 ₂ which corresponds from the computer 11, - [f (t) -t 0] is configured to set the ± △ t ₂ becomes delay correction time.

Further, a fifth embodiment of the device of the present invention will be described with reference to FIG. In this embodiment, a laser oscillator such as L ₂ can be exchanged while continuing to operate. That is, this device is arranged at the equal distance DO known for the distance between the laser oscillators L ₁ , L ₂ , ..., L _n . Then, for example, when the laser oscillator L ₂ is replaced due to a failure or a life, the bypass mirror 21 is provided on the input / output side of the laser oscillator L _2.
˜24 are arranged so as to be bypassed with a predetermined positional relationship, and a spare laser oscillator Lx is arranged between the mirrors 22 and 23.
It is a configuration for obtaining a large output laser light through.

At this time, Da + Db + Dc and Dd + De + Df are set to constant values (preferably multiples of DO) between the mirrors 21 to 24. For example Da + Db
If + Dc = Dd + De + Df = 2DO, the optimum oscillation timing times before and after the bypass change as follows. Laser oscillator L1 L2 L3 L4
, ... Ln Before bypass T1 T1 + t1 T1 + 2t1 T1 + 3t1
,… T1 + (n-1) t1 After bypass T1 T1 + 3t1 T1 + 4t1 T1 + 5t1
,… T1 + (n + 1) t1

Here, T1 is an initial setting value and includes a delay time peculiar to the discharge device. t1 is a value obtained by dividing the distance DO by the speed C of light. When the laser oscillator Lx is not inserted after the bypass by the mirrors 21 to 24, the laser oscillator does not oscillate at T1 + 3t1 and the same applies thereafter.

Therefore, according to the configuration of the above embodiment, when the laser oscillator L ₂ is replaced, for example, the mirrors 21 to 24 and the spare laser oscillator Lx are bypassed to the input / output side of the laser oscillator L _2. This makes it possible to continuously output high-power laser light without stopping the device.
Moreover, at the time of this replacement, if the distances of the respective mirrors 21 to 24 are set in the relationship as described above, the optimum oscillation timing time can be set, and switching can be performed extremely smoothly.

In the above embodiment, one laser oscillator is bypassed, but a plurality of laser oscillators may be replaced at the same time. In this case, therefore, the oscillation timing time by the computer 11 is added by 2t1. With such a software configuration, it is possible to control at the optimum oscillation timing time regardless of the number of exchanged units. Also,
The speed of light C is slightly affected by changes in temperature and atmospheric density. Therefore, by providing a thermometer and an atmospheric pressure gauge, and correcting the speed C of light according to the detected temperature and the detected atmospheric pressure, such an influence can be eliminated.

Further, a plurality of laser oscillators L ₁ ,
L _2, was placed in series ... on the same line, for example, a reflecting mirror 25 as shown in FIG. 7, ... may be configured to place in a meandering shape through the. In addition, the present invention can be modified in various ways without departing from the scope of the invention.

[0046]

As described above, according to the present invention, the following various effects are exhibited.

According to the first aspect of the present invention, the change of the delay time due to the operating period of the laser device is set as a function so that the timing control can be executed without obtaining a feedback signal, and a special calculation by a computer is required. The laser light can be output at an optimal timing time without performing any operation.

Next, in the invention of claim 2, a predetermined indefinite delay time is used for the laser oscillator in the non-exchanged state in the stable region of the delay time after the start of operation, and it is obtained by the delay function for the exchanged laser oscillator. Since the oscillation timing time is obtained by using the given indefinite delay time, even if the laser oscillator after replacement and the laser oscillator without replacement are mixed, the laser light can be reliably output at the optimum oscillation timing time, and Similar to the above, it is not necessary to perform feedback control, and the capacity of the computer can be significantly reduced.

Further, according to the third aspect of the invention, since the oscillation timing time is set by using the indefinite delay time in consideration of the operation period of the laser device and the feedback deviation time due to the actual oscillation operation, when the laser oscillator is replaced. It is possible to oscillate laser light with extremely high efficiency at both non-steady state and steady state. Further, in the invention of claim 4, the laser oscillator can be exchanged while continuing the oscillation output of the laser light.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of the invention according to claim 1.

FIG. 2 is a diagram showing a time setting means in the invention according to claim 1;

FIG. 3 is a configuration diagram showing an embodiment of the invention according to claim 2;

FIG. 4 is a configuration diagram showing an embodiment of the invention according to claim 3;

FIG. 5 is a configuration diagram showing another embodiment of the invention according to claim 3;

FIG. 6 is a configuration diagram showing an embodiment of the invention according to claim 4;

FIG. 7 is a diagram in which a plurality of laser oscillators are arranged in a meandering shape using a mirror.

FIG. 8 is a configuration diagram of a conventional laser device in which a plurality of laser oscillators are arranged in series and in multiple stages.

9 is a configuration diagram of a conventional timing control device applied to the laser device shown in FIG.

FIG. 10 is a diagram showing the relationship between the operating time of the laser device and the indefinite delay time.

FIG. 11 is a configuration diagram of a conventional timing control device considering an indefinite delay time.

[Explanation of symbols]

L _1, L _2, ... ... laser oscillator, Lx ... laser oscillator of the auxiliary, 3 ... master clock source, 4 _1, 4 _2,
……… Thyratron, 5 ₁ , 5 ₂ … Carrent probe, 11… Computer (time setting means), 12 ₁ , 1
2 ₂ , ... Delay unit, 13 ... High-speed stopwatch circuit, 21-24 ... Bypass mirror, 25 ...
mirror.

Claims (4)

[Claims] 1. A timing control device for a laser device, wherein a plurality of laser oscillators are arranged in series and in a multi-stage arrangement, and a delay unit corresponding to these laser oscillators controls oscillation of the corresponding laser oscillator at an optimum oscillation timing time. For the delay unit, in addition to a constant delay time depending on the speed of light and the like, an indefinite delay time obtained from a delay function that represents a delay time that changes after the operation of the laser device reaches a stable region is set. A timing control device comprising: time setting means; and timing time determining means for determining an oscillation timing time from the fixed delay time and the indefinite delay time in each of the delay units. 2. A timing control device for a laser device, wherein a plurality of laser oscillators are arranged in series and arranged in multiple stages, and a delay unit corresponding to these laser oscillators controls oscillation of the laser oscillators at an optimum oscillation timing time. When any laser oscillator is replaced after the stable delay time has been reached due to the passage of time after the start of the operation, the stable range after the start of operation of the laser device is reached for the delay unit corresponding to the replaced laser oscillator. Second time setting means for setting an indefinite delay time obtained from a delay function that expresses a delay time varying up to, while setting the stable delay time for a delay unit corresponding to a non-exchange laser oscillator. A timing control device comprising: 3. A timing control device for a laser device, wherein a plurality of laser oscillators are arranged in series and arranged in multiple stages, and a delay unit corresponding to these laser oscillators controls oscillation of the laser oscillators at an optimum oscillation timing time. A means for extracting a feedback correction time from the deviation between the actual oscillation time of the oscillator and a preset set time, and a constant delay time depending on the speed of light or the like for the delay unit corresponding to the arbitrary laser oscillator, Timing provided with a third time setting means for setting an indefinite delay time obtained from a delay function expressing a delay time that changes until the stable region is reached after the laser device is started, and a third time setting means for setting the feedback correction time. Control device. 4. A timing control device for a laser device, wherein a plurality of laser oscillators are arranged in series and arranged in multiple stages, and a delay unit corresponding to these laser oscillators controls oscillation of the laser oscillators at an optimum oscillation timing time. Of the laser oscillator of the above, it is arranged so as to bypass a plurality of mirrors on the input / output side of the laser oscillator to be replaced, and an auxiliary laser oscillator is arranged on this bypass line, while continuing the operation of the laser oscillator. A timing control device characterized by replacing an arbitrary laser oscillator.