JPH04105379A - Pulsed laser - Google Patents

Abstract

PURPOSE:To make possible a reduction in the size of the whole pulsed laser and to make it possible to increase the efficiency of laser output by a method wherein a magnetic pulse compression circuit is housed in a tank and the tank and all are housed and provided in the interior of a pulsed laser main body. CONSTITUTION:A magnetic pulse compression circuit 3 is provided in the interior of a laser main body 4 along with a discharge part 5. This circuit 3 is connected to a laser power supply 1, which is provided outside of the main body 4, via a cable 2. The circuit 3 is housed in a tank with an insulating oil filled in its interior and the tank and all are housed and provided in the interior of the main body 4.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a pulse laser device in which a magnetic pulse compression circuit of a power supply section and a laser device main body are integrated.

(Prior Art) In recent years, industrial use of extrapolated pulse laser devices such as high-output TEA, TEMA-Co, laser, excimer laser, copper vapor laser, etc. has been considered. Furthermore, these lasers are increasingly required to have high-speed, large-current pulsed power supplies.

In such a pulse power supply, the power burden on the switch elements that open and close large currents is extremely large, so in many cases, the currently used switch elements (for example, thyratrons, thyristors, etc.) are only capable of opening and closing operations. In addition, as a pulsed laser device, the operation delay time is small (number +
Since they are required to have a long life (about 108 shots or more), there are almost no switch elements that are of practical use.

Therefore, recently, attempts have been made to reduce the power burden on switching elements by adding a pulse compression circuit to realize a high-speed, large-current, and high-output pulse power supply.A representative example of this is the magnetic pulse Examples include compression circuits.

This magnetic pulse compression circuit utilizes the saturation of magnetization of a ferromagnetic material such as an iron core.
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FIG. 3 shows an example of such a magnetic pulse compression circuit. That is, the laser power source 30 is connected to a first capacitor 7 via a charging resistor 31, and second and third capacitors 8.9 are connected in parallel to the first capacitor 7. Further, a first saturable reactor 10 is connected in series between the first and second capacitors 7.8, and a second saturable reactor is connected between the second and third capacitors 8.9. 11 are connected in series. Further, a third saturable reactor 12 is connected in series to the third capacitor 9, and the laser discharge section 5 is connected in parallel through this. With this configuration, the first capacitor 7
a first-stage loop from the second capacitor 8 to the second capacitor 8 via the first saturable reactor 10; and a second loop from the second capacitor 8 to the third capacitor 9 via the second saturable reactor 11. A stage loop and a third stage loop table extending from the third capacitor 9 to the laser discharge section 5 via the third saturable reactor J2 are formed. Further, a switch 16 is provided between the first capacitor 7 and the first saturable reactor 10, and is configured to be openable and closable.

The conventional pulse laser device configured in this manner operates as described below. That is, the first capacitor 7 is charged from the laser power source 30 via the charging resistor 31. Here, when the switch 16 is turned on, the voltage between the electrodes of the first capacitor 7 is applied to the series circuit of the first saturable reactor 10 and the second capacitor 8. At this time, since no charge is stored in the second capacitor 8 and the voltage between its poles is almost zero, the voltage between the poles of the first capacitor 7 is between the poles of the first saturable reactor 10. Almost all will be added. As a result, a small current 17 flows between the poles of the first saturable reactor 10. This current 17 excites the first saturable reactor 10, and when the magnetic flux density in the iron core of the first saturable reactor 10 becomes less than the saturation magnetic flux density, the first saturable reactor 10 becomes saturated. Then, since the inductance of the first saturable reactor 10 rapidly decreases, a current 17 flows from the first capacitor 7 through the first saturable reactor 10 in the saturated state, and charges the second capacitor 8. . Note that the frequency of the current 17 flowing through the first stage loop as described in ``1'' is determined by the capacitance value of the first capacitor 7, the inductance value of the first saturable reactor 10 at saturation, and the second capacitor 8. It is almost determined by the capacitance value. Subsequently, as the voltage between the electrodes of the second capacitor 8 increases, a voltage is applied between the electrodes of the second saturable reactor 11, and in the same way, the current 18 flows through the second saturable reactor 11.
flows and reaches saturation. At this time, the charge on the second capacitor 8 is transferred to the third capacitor 9.

Furthermore, the current 19 flows in the third saturable reactor 12 as well, and reaches saturation.

Here, in order to sequentially increase the frequency of the currents 17 to 19 in each stage flowing through each saturable reactor 10 to 12, the inductances of the first to third saturable reactors 10 to 12 at unsaturated and saturated states are sequentially increased. It is said that this is a way to make it smaller. In addition, in order to efficiently transmit the energy stored in each capacitor to the subsequent capacitor, a method is adopted in which the capacitance of the capacitors in each stage is made equal and the values of the saturable reactors 10 to 12 are successively reduced. There is. In this method, the voltage of the loop in each stage is constant, and FIGS.
As shown in (C), the current 17~ flowing through the loop of each stage
The 19 peak values are sequentially amplified and their frequencies are raised. Then, the current 19 of the final stage loop subjected to magnetic pulse compression flows to the laser discharge section 5, which is a load, and causes laser oscillation.

The operation process of saturation and non-saturation of the saturable reactor described above will be explained in detail below with reference to FIG.

Note that FIG. 5 shows the magnetization curve of the iron core that constitutes the saturable reactor. That is, when an excitation current flows from the capacitor at the front stage of the saturable reactor, the operating point of the iron core of the saturable reactor moves from the center point 23 toward the point 24 in FIG. 5. Depending on this excitation current, the operating point or point 2
4, the magnetic flux density in the iron core of the saturable reactor becomes a saturated magnetic flux density layer, and the saturable reactor becomes saturated. At this time, the inductance of the saturable reactor rapidly decreases, so current flows from the preceding capacitor through the saturable reactor in the saturated state to the subsequent capacitor, charging it.

In this way, the operating point of the iron core when the saturable reactor is in the saturated state is located at a location where the magnetizing force H is much larger than point 24, but as the current decreases, it moves to the location where the magnetizing force H is smaller and the point 25, the iron core changes from a saturated state to an unsaturated state. Then, since the inductance of the saturable reactor increases rapidly, the current flowing through the saturable reactor decreases rapidly.

After half a cycle, the operating point when the current becomes zero is point 25, and if it stops at this point, magnetism will remain.

By the way, if the switch 16 is turned on again with the operating point of the iron core at point 25, the operating point of the iron core moves from point 25 to point 24, but since the amount of change in magnetic flux in this case is small, it is not saturated. At this time, the inductance of the saturable reactor cannot be made sufficiently large, and the magnetic pulse compression operation becomes almost impossible. Therefore, once the magnetic pulse compression has been performed, a so-called magnetic reset is performed, which returns the operating point of the iron core from the center point 26 in FIG. I'm trying to do it. Therefore, in the conventional circuit, as shown in FIG. 3, reset devices 20 to 22 are provided in each stage loop. There are various methods for this magnetic reset, but the simplest method is to flow a direct current in the opposite direction so that the operating point of the iron core is at point 26. According to this method, after performing magnetic pulse compression, the operating point of the iron core becomes point 26, so if the next magnetic pulse compression operation is performed in this state, the magnetic flux change will be larger than if it is performed from point 23. , the compression ratio can be increased.

(Problems to be Solved by the Invention) However, the conventional pulse laser device as described in 1- has the following problems to be solved. That is,
Generally, the laser power supply that supplies energy to the laser device main body is installed on the side of the laser device main body, or the laser power supply is equipped with a magnetic pulse compression circuit as shown in Fig. 3. If used, the installation space will be significantly increased. Furthermore, since the portion that electrically connects the laser power source and the laser device main body becomes long, the impedance of the circuit increases and the oscillation efficiency decreases.

The present invention was proposed in order to eliminate the above-mentioned drawbacks, and its purpose is to provide a pulse laser device that can reduce the size of the entire device and increase the efficiency of laser output.

[Structure of the Invention] (Means for Solving the Problems) The present invention provides a magnetic pulse compression circuit comprising a capacitor and a saturable reactor that compresses the time width of a current input from the capacitor and outputs the current. In a pulse laser device having a power supply section and a discharge section for generating laser light, the magnetic pulse compression circuit is housed in a tank, and the tank is housed inside the main body of the pulse laser device. It is something to do.

(Function) According to the pulse laser device of the present invention, by arranging the tank containing the magnetic pulse compression circuit inside the laser device main body, it is possible to downsize the entire laser device.

In addition, the magnetic pulse compression circuit and the discharge section can be placed close to each other, and the electrical wiring from the magnetic pulse compression circuit to the discharge section can be coaxial, reducing circuit impedance and input loss. can be made smaller.

(Example) Hereinafter, an example of the present invention will be specifically described based on FIGS. 1 and 2. Incidentally, the same members as those of the conventional type shown in FIG. 3 are given the same reference numerals, and the description thereof will be omitted.

In this embodiment, as shown in FIG.
is installed. And this magnetic pulse compression circuit 3
is connected via a cable 2 to a laser power source 1 provided outside the laser device main body 4 . Further, the laser beam obtained from the discharge section 5 is configured to be outputted from an output window 6. The magnetic pulse compression circuit 3 is housed in a tank filled with insulating oil, and the tank is housed inside the laser device main body 4.

FIG. 2 shows details of the magnetic pulse compression circuit 3 and discharge section 5 disposed inside the laser device main body 4. As shown in FIG.

That is, the first. Second capacitor 7.8 and first second saturable reactor 10
．． 11 are connected almost coaxially. Further, a return conductor connecting the magnetic pulse compression circuit 3 and the discharge section 5 is also arranged substantially coaxially. On the other hand, the discharge section 5 is composed of a pair of electrodes 14 and 15 arranged opposite to each other and a capacitor 13 arranged on the side thereof.

In the pulse laser device of this embodiment having this tub-like configuration, laser light is output as follows. That is,
From the laser power supply 1 to the laser device main body 4 via the cable 2
When a current is supplied to the magnetic pulse compression circuit 3 disposed inside, the final stage loop current subjected to magnetic pulse compression as described above is supplied to the discharge section 5, causing laser oscillation. Then, laser light is output from the output window 6.

In this way, according to this embodiment, the magnetic pulse compression circuit 3 is housed inside the laser device main body 4, so that the entire device can be downsized. Moreover, the first . the second capacitor 7.8 and the first capacitor 7.8;
Since the second saturable reactors 10 and 11 are connected substantially coaxially, the impedance of the magnetic pulse compression circuit can be kept low. Furthermore, the return conductor connecting the magnetic pulse compression circuit 3 and the discharge section 5 is arranged almost coaxially, and by arranging both in close proximity, the return conductor can be shortened. Since impedance can also be reduced, the oscillation efficiency of the pulsed laser device can be significantly improved.

[Effects of the Invention] As described above, according to the present invention, the magnetic pulse compression circuit is housed in a tank, and the tank as a whole is housed inside the main body of the pulse laser device, thereby reducing the size of the entire device. It is possible to provide a pulsed laser device that can increase the efficiency of laser output.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram showing an embodiment of the pulse laser device of the present invention, Fig. 2 is a circuit diagram of the magnetic pulse compression circuit and discharge section inside the main body of the pulse laser device of the present invention, and Fig. 3 is a general diagram. Circuit diagram of magnetic pulse compression circuit, Fig. 4 (A) to (C)
5 is a diagram showing the current value flowing through each stage loop of the magnetic pulse compression circuit, and FIG. 5 is a diagram showing the magnetization curve of the iron core constituting the saturable reactor. DESCRIPTION OF SYMBOLS 1... Laser power supply, 2... Cable, 3... Magnetic pulse compression circuit, 4... Laser device main body, 5... Discharge part, 6... Output window, 7... First Capacitor, 8... Second capacitor, 9... Third capacitor, 1°... First saturable reactor, 11... Second saturable reactor, 12... Third capacitor Saturable reactor, 13... Capacitor, 14.15... Electrode,
16...Switch, 17...1st stage loop current, 18
The loop current of the second stage of the mountain, 19...the loop current of the third stage,
20-22... Reset device, 30... Laser power supply, 31... Charging resistor.

Claims (1)

[Claims] A capacitor and a current input from the capacitor,
In a pulse laser device, the power supply unit includes a magnetic pulse compression circuit comprising a saturable reactor that compresses the time width and outputs the pulse, and also has a discharge unit that generates laser light, wherein the magnetic pulse compression circuit is located in a tank. What is claimed is: 1. A pulse laser device, characterized in that the tank thereof is housed inside a main body of the pulse laser device.