JPH07288357A - Gas laser oscillation system - Google Patents

Abstract

PURPOSE:To output highly efficient, high power laser light by placing pairs of a plurality of divided major electrodes on the same optical axis, and causing major discharge simultaneously in these pairs of the major electrodes. CONSTITUTION:The transit time for charge to be transferred from respective major capacitors (32, 33) to respective pairs of pin electrodes (13a, 13b, 23a, 23b) is adjusted by means of respective adjusting coils (36, 37) so that the pairs of the pin electrodes (13a, 13b, 23a, 23b) will be simultaneously ignited. This causes simultaneous preliminary ionization in pairs of major electrodes (11a, 11b, 21a, 21b). Subsequently, major discharge is simultaneously caused, and the beams of highly efficient, high power laser light are outputted on the same optical axis.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas laser oscillator which oscillates a large laser output with high efficiency.

[0002]

2. Description of the Related Art In order to obtain a large output laser oscillation, a long laser tube, that is, a long main electrode pair is required. Generally, when a main electrode is manufactured by machining or the like, there are restrictions on processing accuracy and the like. The length of the upper main electrode is limited to about 1 m.

Therefore, when a main electrode pair having a length close to 2 m is required, it is necessary to divide into two or three formulas. Figure 3
FIG. 3 is a configuration diagram of a gas laser oscillator for a high-power laser using the two types of main electrode pairs. In the two types of gas laser tubes 10 and 20 whose optical axes are aligned with each other, a main electrode pair 11 is provided.
a, 11b and 21a, 21b are arranged.

These main electrode pairs 11a, 11b and 21
a and 21b have peaking capacitors 12a and 12
The pin electrode pairs 13a, 13b and 23a, 23b for preionization are connected via b and 22a, 22b.

These pin electrode pairs 13a, 13b and 23
a and 23b are main electrode pairs 11a, 11b and 2 respectively.
1a, 21b along the longitudinal direction, and each main electrode pair 11
It is arranged at a position where a discharge space of a, 11b and 21a, 21b is desired.

On the other hand, the thyratrons 15 and 25 are connected to the high voltage power source + HV via the charging resistors 14 and 24, respectively. Of these, the anode side of the thyratron 15 is connected to the main electrode 11a via the main capacitor 16 and the charging coil 17 is connected.

Further, the anode side of the thyratron 25 is connected to the main electrode 21a via the main capacitor 26 and the charging coil 27 as in the above. With such a configuration, each charging resistor 14 from the high voltage power source + HV,
The main capacitors 16 and 26 are charged through 24 and the charging coils 17 and 27.

After completion of this charging, each thyratron 15 and 2
When 5 are fired at the same time, the electric charges stored in the main capacitors 16 and 26 are charged to the peaking capacitors 12a and 1a, respectively.
2b and 22a, 22b, and spark discharge is generated in the pair of pin electrodes 13a, 13b and 23a, 23b for preionization. Due to this spark discharge, the discharge space between each main electrode pair 11a, 11b and 21a, 21b is preionized.

At the same time, when the applied voltage to each main electrode pair 11a, 11b and 21a, 21b increases and reaches a predetermined voltage, these main electrode pairs 11a, 11b and 21a,
A main discharge occurs between 21b.

By this main discharge, each gas laser tube 10, 2
The gas species in 0 is excited, laser resonance occurs in a laser resonator (not shown), and laser light is output. When the two types of main electrode pairs are used as described above, the main capacitors 16 and 26, the thyratrons 15 and 25, and the charging resistors 14 and 24 are required.
It is necessary to activate 25 at the same time.

In general, switching elements such as the thyratrons 15 and 25 have subtle variations in their individual characteristics, so that they do not always fire at the same time. According to a detailed experiment, XeC using the circuit shown in FIG.
In the case of an excimer laser, two types of thyratrons 15,
The jitter between 25 is less than 10 ns (10 × 10 ⁻⁸ s).

When a larger jitter is included,
Despite arranging two types of main electrode pairs on the same optical axis, 1
In some cases, a laser output smaller than that obtained with the pair of main electrodes is obtained.

The pin electrode pairs 13a, 13b and 23a, 23b arranged in the gas laser tubes 10, 20 are also provided.
If the shape of each is different or each peaking capacitor 12
If the constants of a, 12b and 22a, 22b, and the length of each main electrode pair 11a, 11b and 21a, 21b are different, even if each thyratron 15, 25 is simultaneously (10n
Even if the firing operation is performed with a jitter of s or less), the discharge time may be different and sufficient laser oscillation may not be obtained.

[0014]

When the main electrode pair is divided into a plurality of types as described above, if a large jitter is included, it is 1
In some cases, a laser output smaller than that obtained with the pair of main electrodes is obtained.

Further, each main electrode pair 11a, 11b and 21
When the lengths of a and 21b are different, each thyratron 15,
Even if 25 are fired at the same time, the discharge generation time may be different and sufficient laser oscillation may not be obtained.

Therefore, the present invention provides a gas laser oscillating device capable of producing a high-efficiency and high-power laser beam by simultaneously generating a main discharge by a plurality of main electrode pairs which are divided into a plurality of types and are arranged on the same optical axis. The purpose is to do.

[0017]

According to the first aspect of the present invention, a plurality of main electrode pairs and a plurality of preionization electrodes for these main electrode pairs are arranged in the gas laser tube, and the accumulated charges of the main capacitor are transferred to the preionization electrodes. In the gas laser oscillation device that pre-ionizes between each main electrode and then generates each main discharge between each main electrode to output a laser beam whose optical axis coincides with each other, the transfer of the charge transferred to each pre-ionization electrode A gas laser oscillating device, which is provided with an adjusting coil for adjusting the time and simultaneously igniting each of the preionization electrodes, to achieve the above object.

According to the present invention, a plurality of main electrode pairs and a plurality of preionization electrodes for the main electrode pairs are arranged in the gas laser tube, and the accumulated charges of the plurality of main capacitors are respectively transferred to the preionization electrodes. Pre-ionize between the main electrodes,
Then, in a gas laser oscillator that generates each main discharge between each main electrode and outputs a laser beam whose optical axis coincides with each other, the transfer time of the charge transferred to each preionization electrode is adjusted and the point of each preionization electrode is adjusted. A gas laser oscillating device, which is provided with an adjusting coil having simultaneous arcs and one switching element for simultaneously transferring the accumulated charges of each main capacitor to a preionization electrode, to achieve the above object.

According to the third aspect, a plurality of main electrode pairs and a plurality of preionization electrodes for these main electrode pairs are arranged in the gas laser tube, and the accumulated charges of the plurality of main capacitors are respectively transferred to the preionization electrodes. Pre-ionize between the main electrodes,
Then, in a gas laser oscillator that generates each main discharge between each main electrode and outputs a laser beam whose optical axis coincides with each other, the transfer time of the charge transferred to each preionization electrode is adjusted and the point of each preionization electrode is adjusted. Adjustment coils with simultaneous arcs, multiple switching elements connected in parallel to each main capacitor, and simultaneously switching the accumulated charge of each main capacitor to the preionization electrode, and triggers for these switching elements respectively. Trigger applying means for giving each trigger signal whose waveform and its timing are adjusted within a predetermined time,
A gas laser oscillating device which has the above-mentioned object and is intended to achieve the above object.

According to claim 4, the constant of the adjustment coil is Csi, where Csi of each main capacitor, Cpi of each peaking capacitor connected to each preionization electrode, and the inductance Li of the adjustment coil itself. Cpi.Li/(Csi+Cpi)=Csi+1.Cpi+1.Li+1/(Csi+1+Cpi+1) is selected.

According to the fifth aspect of the present invention, the assist cores, which adjust the timings of the currents flowing through the plurality of switching elements and flow uniform currents, are connected to the respective switching elements. According to claim 6, the main electrodes on the cathode side of the plurality of main electrode pairs are short-circuited.

[0022]

According to the first aspect of the present invention, when the main electrode pairs are preionized by the discharge in the preionization electrode, the transfer time of the electric charge transferred from the main capacitor to the preionization electrode is adjusted by the adjusting coil. Ignition operation of the preionization electrode is performed simultaneously.

As a result, preionization is simultaneously performed in each of the plurality of main electrode pairs, and subsequently a main discharge is generated between the main electrode pairs, so that a high-efficiency and high-power laser beam whose optical axis is coincident is generated. Is output.

According to the second aspect, when one switching element is operated, the accumulated charge of each main capacitor connected to each main electrode pair is transferred to each preionization electrode. At this time, the transfer time of the charges transferred to the preionization electrodes is adjusted by the adjustment coil, and the preionization electrodes simultaneously fire.

As a result, preionization is simultaneously performed in each of the plurality of main electrode pairs, and subsequently, main discharge is generated between each main electrode pair, and laser light whose optical axes coincide with each other is output.
According to claim 3, for the plurality of switching elements,
When each trigger signal with its trigger waveform and its timing adjusted within a predetermined time is given, the accumulated charge of each main capacitor connected to each main electrode pair is transferred to each preionization electrode by the operation of these switching elements. Transition.

At this time, the transfer time of the charges transferred to the preionization electrodes is adjusted by the adjustment coil, and the preionization electrodes simultaneously fire. As a result, preionization is simultaneously performed in each of the plurality of main electrode pairs, and subsequently, a main discharge is generated between each main electrode pair, and laser light whose optical axes match each other is output.

According to the fourth aspect, the constant of the adjusting coil is Csi.Cpi.Li/(Csi+Cpi)=Csi+1.Cpi+1.Li+1/(Csi+1+Cpi+1) as described above. If selected so as to satisfy the relationship, it is possible to simultaneously generate discharges in the respective preionization electrodes and perform preionization.

According to the present invention, by connecting the assist core to each of the plurality of switching elements, it is possible to adjust the timing of the current flowing through each switching element to make the current uniform and reduce the power consumption during the operation of the switching elements. it can.

According to the sixth aspect, by short-circuiting the main electrodes on the cathode side of the plurality of pairs of main electrodes, even if the voltage on the cathode side of each main electrode pair is different due to the jitter of each switching element, Can be forced to match.

[0030]

【Example】

(1) Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. The same parts as those in FIG. 3 are designated by the same reference numerals, and detailed description thereof will be omitted. FIG. 1 is a configuration diagram of a gas laser oscillator for a high-power laser using two types of main electrode pairs. One thyratron 31 is connected to the high voltage power supply + HV via a charging resistor 30.

Main capacitors 32 and 33 are connected in parallel on the anode side of the thyratron 31, and the main capacitor 32 is connected to the main electrode 11a, and the main capacitor 3
3 is connected to the main electrode 21a. The main capacitors 32 and 33 have charging coils 34 and 35, respectively.
Are connected.

Adjustment coils 36 and 37 are provided in the respective charging circuits each including the high voltage power source + HV, the charging resistor 30, the main capacitors 32 and 33, and the charging coils 34 and 35.
Are connected.

These adjusting coils 36 and 37 adjust the transfer time of the charges transferred to each pin electrode pair 13a, 13b and 23a, 23b, and simultaneously ignite each pin electrode pair 13a, 13b and 23a, 23b. It is what

The constants of these adjusting coils 36 and 37 are
Each capacitance Csi of each main capacitor 32, 33, series capacitance Cpi of each peaking capacitor 12a, 12b and 22a, 22b, inductance L of each adjustment coil 36, 37.
i is selected so as to satisfy the relationship of Csi · Cpi · Li / (Csi + Cpi) = Csi + 1 · Cpi + 1 · Li + 1 / (Csi + 1 + Cpi + 1) (1). It should be noted that i and i + 1 are numbers given to the gas laser tubes 10 and 20, respectively.

Next, the operation of the apparatus configured as described above will be described. From the high voltage power supply + HV through the charging resistor 30,
The main capacitors 32 and 33 are charged through the charging circuits of the adjustment coils 36 and 37 and the charging coils 34 and 35.

After the end of this charging, when the thyratron 31 is ignited, the electric charges accumulated in the main capacitors 32 and 33 are transferred to the peaking capacitors 12a, 12b and 22a, 22b through the adjusting coils 36, 37. To do.

At this time, the adjustment coils 36 and 37 are
Since they are selected as constants that satisfy the above equation (1), the charge transfer time, that is, each peaking capacitor 1
The charging times of 2a, 12b and 22a, 22b are the same.

As a result, each pin electrode pair 13a, 13b
23a and 23b are simultaneously ignited to generate a spark discharge. Due to this spark discharge, each main electrode pair 11a,
The discharge space between 11b and 21a, 21b is preionized at the same time.

As a result, when the applied voltage of each main electrode pair 11a, 11b and 21a, 21b becomes high and reaches a predetermined voltage, these main electrode pairs 11a, 11b and 21a, 21b.
Main discharge occurs at the same time.

Each gas laser tube 1 is produced by these main discharges.
The gas species in 0 and 20 are excited, laser resonance occurs in a laser resonator (not shown), and laser light is output. As described above, in the first embodiment, the transfer time of the charges transferred from the main capacitors 32, 33 to the pin electrode pairs 13a, 13b and 23a, 23b is adjusted by the adjustment coils 36, 37. Therefore, the firing operation of each pin electrode pair 13a, 13b and 23a, 23b is performed at the same time, and the preionization is simultaneously performed in each of the two types of main electrode pairs 11a, 11b and 21a, 21b. Each main discharge is generated at the same time, and a high-efficiency and high-power laser beam with an aligned optical axis can be output.

The constants of the adjusting coils 36 and 37 are
Since the selection is made so as to satisfy the relation of the above formula (1), even if each main electrode pair 11a, 11b and 21 of the two formulas is selected,
The lengths of a and 21b are different, and the main capacitors 32 and 33 are
And each peaking capacitor 12a, 12b and 22
Even if the respective capacitances of a and 22b are different and the timing of charge transfer between the two is different, these can be corrected and preionization can be performed at the same time. (2) Next, a second embodiment of the present invention will be described with reference to the drawings. The same parts as those in FIG. 1 are designated by the same reference numerals, and detailed description thereof will be omitted.

FIG. 2 is a block diagram of a gas laser oscillator for a high-power laser using two types of main electrode pairs. A charging resistor 40 is connected to one of the high-voltage power supplies + HV, and four thyratrons 42a to 42d are connected in parallel to the charging resistor 40 via four assist cores 41a to 41d. In the figure, only the assist cores 41a and 41d and the thyratrons 42a and 42d are shown.

The charging resistor 43 is connected to the other high voltage power source + HV in the same manner as described above, and four thyratrons 45a to 45d are connected to the charging resistor 43 via four assist cores 44a to 44d.
45d are connected in parallel. In addition, each assist core 4
Only 4a, 44d and the respective thyratrons 45a, 45d are shown.

These thyratrons 42a to 42d and 4
5a to 45d receive a trigger signal from the trigger applying means 46 to perform an ignition operation. This trigger applying means 46 is provided for each thyratron 42a to 42d and 45.
It has a function of adjusting the trigger waveform of each trigger signal given to a to 45d and its timing within the jitter of 10 ns.

Each assist core 41a-41d and 44a
-44d are thyratrons 42a-42d and 45a, respectively.
Each thyratron 42 while reducing the power consumption of ~ 45
It has a function of adjusting the timings of the currents flowing through a to 42d and 45a to 45 and distributing the uniform currents.

These assist cores 41a to 41d and 4
An amorphous nonlinear magnetic material (for example, Toshiba TN-111, trade name) is used as the material of 4a to 44d. Then, these assist cores 41a to 41d and 4
4a to 44d use the non-linear effect to delay the timing of the current flow and reduce the switch loss in each of the thyratrons 42a to 42d and 45a to 45.

Further, each of the adjusting coils 36 and 37 has the above-mentioned formula.
It is selected as a constant that satisfies the relationship of (1). A charging coil 47 is commonly connected to each circuit of the high voltage power source + HV to the main capacitors 32 and 33 and the adjustment coils 36 and 37 to form a charging circuit.

The main electrodes 11a and 21a on the cathode side are
Common connection or short circuit. For this short circuit, for example, a low inductance lead plate is used. This short-circuit connection is made for each thyratron 42a-42d and 45a-45.
When the voltages applied to the main electrodes 11a and 21a are different due to the jitter of d, this is a circuit for forcibly matching them.

Next, the operation of the apparatus configured as described above will be described. Each high voltage power supply + HV to each charging resistor 40
9, 43, adjustment coils 36, 37, charging coil 47
Through, the main capacitors 32 and 33 are charged.

After this charging is completed, each trega signal from the trigger applying device 46 is sent to each thyratron 42a to 42d and 45.
a to 45d, these thyratrons 42a
˜42d and 45a to 45d perform the firing operation.

At this time, the trigger waveform and the timing of each trigger signal are adjusted within the jitter of 10 ns. These thyratrons 42a to 42d and 4
By the ignition operation of 5a to 45d, each main capacitor 32,
The electric charge accumulated in 33 is adjusted by the adjustment coils 36, 3
7 to the respective peaking capacitors 12a, 12b and 22a, 22b.

At this time, the adjustment coils 36 and 37 are
Since they are selected as constants that satisfy the above equation (1), the charge transfer time, that is, each peaking capacitor 1
The charging times of 2a, 12b and 22a, 22b are the same.

Along with this, each of the assist cores 41a to 41d
And 44a to 44d are connected, the timing of the current flowing through each thyratron 42a to 42d and 45a to 45d is delayed, and these thyratrons 42a to 42d are connected.
And 45a to 45 reduce the switch loss.

That is, each thyratron 42a-42d
And 45a to 45d are ignited, and the current flows after the voltage across the terminals of the thyratron has dropped sufficiently.
Thereby, each thyratron 42a-42d and 45a
The current is shunted evenly to ~ 45d.

In this way, the respective main capacitors 32, 33
When the charges accumulated in the
a, 13b and 23a, 23b are simultaneously fired to generate a spark discharge.

By this spark discharge, each main electrode pair 11
The discharge space between a, 11b and 21a, 21b is preionized at the same time. As a result, each main electrode pair 11a, 11b
And 21a, 21b, when the applied voltage increases and reaches a predetermined voltage, these main electrode pairs 11a, 11b and 21a, 2
Main discharge occurs simultaneously during 1b.

At this time, the main electrodes 11a and 21 on the cathode side are formed.
Since a is short-circuited, each thyratron 42a-4a
Each main electrode 11 due to the jitter of 2d and 45a to 45d
Even if the voltages applied to a and 21a are different, this is forcibly matched.

By these main discharges, each gas laser tube 1
The gas species in 0 and 20 are excited, laser resonance occurs in a laser resonator (not shown), and laser light is output. As described above, in the second embodiment, each of the main capacitors 32 is provided with eight thyratrons 42a to 42d and 45a to 45d by providing each trigger signal whose trigger waveform and its timing are adjusted within the jitter of 10 ns. , 33 to charge each pin electrode pair 13
a, 13b and 23a, 23b to perform the firing operation at the same time, and each of the two types of main electrode pairs 11a, 11b and 21a, 21
In b, the preionization is generated at the same time, and then the main discharge is generated to output the laser light with the coincident optical axis. Therefore, eight thyratrons 42a to 42d and 45a to
Each pin electrode pair 13a, 13b while suppressing the 45d jitter
And the firing operation of 23a and 23b can be performed simultaneously.

Further, as in the first embodiment, the constants of the adjusting coils 36 and 37 are selected so as to satisfy the relation of the above expression (1), and therefore, even if the main electrodes of the two expressions are used, Pair 11
a, 11b and 21a, 21b have different lengths, and each main capacitor 32, 33 and each peaking capacitor 12
Even if the respective capacitances of a, 12b and 22a, 22b are different and the timings of charge transfer between the two are different, these can be corrected and preionization can be performed at the same time.

In addition, each main electrode pair 11 on the cathode side
Since a, 11b and 21a, 21b are short-circuited,
Each main electrode pair 11a, 11b and 21a, 2 due to the jitter of each thyratron 42a-42d and 45a-45d.
Even if the voltage of 1b is different, it is possible to force them to coincide with each other and simultaneously generate the main discharges at the respective main electrode pairs 11a, 11b and 21a, 21b.

Therefore, a high-efficiency and high-output laser beam whose optical axis coincides can be output. In addition, the assist cores 41a to 41
Since d and 44a to 44d are connected, the currents flowing through the thyratrons 42a to 42d and 45a to 45d can be made uniform, and the thyratrons 42a to 42d and 45a can be made uniform.
It is possible to reduce the power consumption during the operation of up to 45d. As a result, the power consumption of the thyratron does not become too large and it does not overheat and malfunction.

The present invention is not limited to the above embodiments, but may be modified as follows. For example, in each of the above embodiments, a gas laser oscillator using two sets of main electrode pairs has been described, but it may be applied to a gas laser oscillator using two or more sets of main electrode pairs. Also, instead of thyratron, SCR, GTO, IGBT, MGT, M
A semiconductor switch such as an OS-FET and a magnetic pulse compression circuit (MPC) may be used.

[0063]

As described above in detail, according to the present invention, a main discharge is simultaneously generated by a plurality of main electrode pairs which are divided into a plurality of types and are arranged on the same optical axis, so that a laser of high efficiency and a large output is produced. A gas laser oscillator capable of outputting light can be provided.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a first embodiment of a gas laser oscillator according to the present invention.

FIG. 2 is a configuration diagram showing a second embodiment of a gas laser oscillator according to the present invention.

FIG. 3 is a block diagram of a conventional device.

[Explanation of symbols]

10, 20 ... Gas laser tube, 11a, 11b, 21a, 21b ... Main electrode pair, 12a, 12b, 22a, 22b ... Peaking capacitor, 13a, 13b, 23a, 23b ... Pin electrode pair, 31 ... Thyratron, 32, 33 ... Main capacitor, 34, 35 ... Charging coil, 36, 37 ... Adjustment coil, 41a-41d, 44a-44d ... Assist core, 42a-42d, 45a-45d ... Thyratron, 46 ... Trigger applying means.

Claims (6)

[Claims] 1. A gas laser tube is provided with a plurality of main electrode pairs and a plurality of preionization electrodes for the main electrode pairs, and the charges accumulated in a main capacitor are transferred to the preionization electrodes to preionize between the respective main electrodes. Then, subsequently, in the gas laser oscillating device for generating each main discharge in each of the main electrode pairs and outputting laser light whose optical axis is matched, the transfer time of the charges transferred to each of the preliminary ionization electrodes is adjusted to A gas laser oscillating device comprising: an adjusting coil for simultaneously igniting a preliminary ionizing electrode. 2. A plurality of main electrode pairs and a plurality of preionization electrodes for the main electrode pairs are arranged in the gas laser tube, and the accumulated charges of the plurality of main capacitors are respectively transferred to the preionization electrodes so that the main electrodes are separated from each other. In a gas laser oscillator that pre-ionizes, and subsequently outputs each main discharge between the main electrodes to output laser light whose optical axis coincides with each other, adjusts the transfer time of charges transferred to each pre-ionization electrode. Gas laser oscillation, comprising: an adjusting coil for simultaneously igniting each of the preionization electrodes, and one switching element for simultaneously transferring the accumulated charge of each of the main capacitors to the preionization electrode. apparatus. 3. A plurality of main electrode pairs and a plurality of preionization electrodes for the main electrode pairs are arranged in the gas laser tube, and the accumulated charges of the plurality of main capacitors are respectively transferred to the preionization electrodes so that between the main electrodes. In a gas laser oscillator that pre-ionizes, and subsequently outputs each main discharge between the main electrodes to output laser light whose optical axis coincides with each other, adjusts the transfer time of charges transferred to each pre-ionization electrode. And a plurality of switching coils that are connected in parallel to each of the main capacitors and that simultaneously transfer the accumulated charge of each of the main capacitors to the preionization electrode. An element, and a trigger applying means for applying a trigger waveform to each of these switching elements and each trigger signal whose timing is adjusted within a predetermined time, A gas laser oscillating device comprising: 4. The constant of the adjusting coil is Csi · Cpi · Li, where Csi of each main capacitor, Cpi of each peaking capacitor connected to each preionization electrode, and the inductance Li of the adjusting coil itself. 4. The gas laser oscillation according to claim 1, 2 or 3, which is selected so as to satisfy a relationship of /(Csi+Cpi)=Csi+1.Cpi+1.Li+1/(Csi+1+Cpi+1). apparatus. 5. The gas laser oscillator apparatus according to claim 3, wherein the assist cores that adjust the timings of the respective currents flowing through the plurality of switching elements and flow uniform currents are connected to the respective switching elements. 6. The gas laser oscillator according to claim 3, wherein a main electrode on the cathode side of the plurality of main electrode pairs is short-circuited.