JPH04177777A - Pulse laser generating equipment - Google Patents

Abstract

PURPOSE:To shorten the rise time of a large current pulse, and improve laser efficiency, by connecting a power supply.switch part with a laser oscillator part whose energy transmission means are isolated, by using conductors. CONSTITUTION:A switch 1 is fixed so as to be adjacent to a high voltage power supply 4. A part (a) between the switch 1 and a capacitor 2 for pulse generation, a part (b) between a peaking capacitor 3 and the other end of the switch 1, and a part (c) between the peaking capacitor 3 and the high voltage power supply 4 are constituted by using flat plates (conductor plates) 7A, as energy transmitting means. By constituting the switch 1 in this manner, inductance is remarkably reduced. By connecting the switch 1 with a discharge part 6 by using three flat plates 7A as shown in figure, the inductance of a circuit is reduced to one-half. Thereby the rise time of large current pulse is shortened, and laser efficiency is improved.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a pulsed laser generator.

[Conventional technology]

Figure 5 shows, for example, the excitation circuit diagram of a conventional excimer laser shown in the Institute of Electrical Engineers of Japan Technical Report (Part ■) No. 217 (Current Status of Short Wavelength Lasers), page 5, published in April 1986, and Figure 6. 1 is a cross-sectional view showing the structure of a conventional pulsed laser generator. In the figure, 1 is a switch such as a thyratron, 2 is a pulse generation capacitor, and 3 is a peaking capacitor, which are connected in parallel to main electrodes 6A and 6B, which will be described later. Reference numeral 4 is a high-voltage power supply that is composed of a single unit and supplies high voltage through a cable, 5 is a charging resistor connected in parallel to the peaking capacitor 3, and 6 is equipped with main electrodes 6A and 6B, which repeatedly discharge to generate laser light. In the discharge section, 8 is a fan for stirring the gas filled in the discharge section 6, and 9 is a cooling heat exchanger. Next, the operation will be explained. First, when a positive voltage is applied to the pulse generating capacitor 2 from the high voltage power supply 4, a charging current flows through the charging resistor 5, and the pulse generating capacitor 2 is charged to the polarity shown. Here, switch 1
When turned on, the pulse generation capacitor 2 starts discharging, a discharge current flows through the peaking capacitor 3, and energy transfer occurs. When the charge stored in the pulse generation capacitor 2 is transferred to the peaking capacitor 3, discharge is subsequently started between the main electrodes 6A and 6B, and a discharge current flows to the discharge section 6. In the excimer laser, a preliminary discharge is performed prior to this main discharge, but the electrodes and circuits for this are omitted. Therefore, when energy is injected from the peaking capacitor 3, a laser is generated due to the main discharge generated between the main electrodes 6A and 6B. In a laser device such as an excimer laser having a small discharge resistance (for example, 0.2Ω), the voltage across the peaking capacitor 3 has an oscillating waveform and a reverse voltage is generated.

[Problem to be solved by the invention]

Conventional pulsed laser generators are configured as described above, and although the thyratron as a switch has the advantage of being able to control large currents, it is difficult to reach the conductive state due to the large inductance that occurs when large currents flow. Delays the rise. Furthermore, when using a thyratron to reduce the efficiency of laser generation, there is a problem in that it is necessary to bring the thyratron and the discharge section as close as possible to reduce the inductance of the circuit. This invention was made to solve the above-mentioned problems, and forms a low impedance circuit with a structure in which the discharge part and the high voltage power supply are separated,
Furthermore, the present invention aims to provide a pulsed laser generator configured by connecting a plurality of switches in series and parallel to each other in a pulse circuit.

[Means to solve the problem]

The pulsed laser generator according to the invention described in claim (1) includes a high-voltage power supply that applies a high voltage necessary for laser output pulse generation, and electrical energy connected in parallel to this high-voltage power supply and stored in a pulse generation capacitor. a power source/sinch unit comprising a switch that captures the discharge of the pulse generating capacitor; a laser oscillating unit having a discharging unit that discharges the accumulated energy of the peaking capacitor that is charged in response to the energy transfer of the pulse generating capacitor and outputs a laser; Energy transmission means is provided for connecting between the high voltage output terminal of the power supply/switch section and the pulse generation capacitor terminal of the laser oscillation section and between the ground terminal of the power supply/switch section and the ground terminal of the laser oscillation section. It is something. The pulsed laser generator according to the invention described in claim (2) also includes a high-voltage power supply that applies a high voltage necessary for generating pulses for laser output, and a high-voltage power supply that is connected in parallel to the high-voltage power supply and accumulates in a pulse generation capacitor. A laser oscillation device comprising: a power supply/switch section consisting of a switch that captures the discharge of electrical energy; and a discharging section that discharges the energy accumulated in the peaking capacitor that is charged in response to the energy transfer of the pulse generation capacitor and outputs a laser beam. and the above 6
A coaxial/energy transmission means is provided, in which the core wire is covered with a dielectric material which also serves as a connection conductor between the pulse generation capacitor, the power supply/switch section, and the laser oscillation section, and the dielectric material is further covered with a metal jacket. It was established. The pulsed laser generator according to claim (3) also includes a high-voltage power supply that applies a high voltage necessary for generating pulses for laser output, and a high-voltage power supply that is connected in parallel to the high-voltage power supply to generate electrical energy stored in a pulse generation capacitor. a power supply/switch section comprising a switch that promotes discharging; a laser oscillation section having a discharging section that outputs laser by discharging the accumulated energy of the peaking capacitor that is charged in response to energy transfer of the pulse generation capacitor; A plate-shaped capacitance/energy transmission means is provided which serves as a connection conductor between a pulse generation capacitor, a power supply/switch section, and a laser oscillation section, and is press-contacted between flat plates via a dielectric.

[Effect]

The energy transmission means in the invention described in claim (1) is one in which a separate power supply/switch section and a laser oscillator section are connected by a conductor, and the energy transmission means in the invention described in claim (2) and claim (
3) The coaxial/energy transmission means and the plate-shaped capacitor/energy transmission means in the invention described above are constructed as parts that serve both as a pulse generation capacitor and a connecting conductor, and are connected between the separate power supply/switch section and the laser oscillator section. Since they are configured to be treated and connected as one circuit component, they act to reduce inductance, increasing the rise speed of the large current flowing through the switch.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, the same parts as in FIG. 5 are shown with the same reference numerals. In FIG.
It is a flat plate as a conductor. Next, the operation will be explained. Since the overall operation of the circuit is the same as that described in the prior art, the explanation will be omitted here, and the structural differences will be described below. As shown in the figure, the structure of the laser device is separated into a discharge section 6, a high voltage power supply 4, and a switch 1. The switch 1 is, for example, a solid-state switch formed by stacking a plurality of FET (field effect transistor) modules in series and parallel as a block, and arranged on the high voltage power supply 4 side. In the case of the illustrated circuit, switch groups A2, B2, C, B, E, and B are all blocks stacked in series in multiple stages and arranged in parallel to form one switch 1. The switch 1 is fixed close to the high voltage power source 4, and the distance a between the switch 1 and the pulse generating capacitor 2, and the distance between the peaking capacitor 3 and the other end of the switch 1 and the high voltage power source 4 and c are connected. Flat plate 7 as a means of energy transmission
They are connected at A (for reference, a, b, and c are shown in Figure 5). By configuring the switch 1 in this manner, the inductance is greatly reduced. Furthermore, by connecting the switch 1 and the discharge section 6 with three flat plates 7A as shown, the inductance of the circuit is reduced by half. Note that the number of flat plates 7A is not necessarily limited to three, but may be two in the main body 1 for reducing inductance, or other flat plates. Further, FIG. 2 shows an example in which a plurality of coaxial cables 7B are used in parallel instead of the flat plate 7A. In this way, when coaxial cable 7B is used, the power supply
The degree of freedom in arranging the switch section 10 and the laser oscillation section 117 is greatly improved. FIG. 3 shows another embodiment. FIG. 3A shows a conceptual diagram of the overall configuration, and FIG. 3B shows the structure of the coaxial energy transmission means 20. The coaxial/energy transmission means 20 is a coaxial cable consisting of a core wire 21 and a jacket metal 24, covered with a shield wire 22, and a capacitor 2 disposed on the power supply side and a capacitor 3 disposed on the main electrode side. connect between In this case, the energy transmission means 20 also serves to shape the high voltage pulse, increasing the efficiency of the laser. cloak metal 24
is provided to reduce noise generated during transmission. Incidentally, since the capacitance of the pulse generating capacitor 2 used in the excimer laser device is usually about 30 to 60 nanofarads, sufficient capacitance can be obtained even with this structure. FIG. 4(A) shows another embodiment using the plate-shaped capacitance/energy transmission means 30, in which case the dielectric 23
It has a sandwich structure in which flat plates 25A and 25B, which are conductors, are pressed into plate shape from both sides. That is, flat plate 2
The dielectric 23 between 5A and 25B is placed as close as possible to form an electric field, and has the functions of a connecting conductor and a pulse generating capacitor 2. In FIG. 4, (B) is a mounting array when applied to a circuit. Capacitance can be adjusted by selecting the horizontal dimensions of the fir. The above embodiment includes a pulse generation capacitor 1, a coaxial energy transmission means 20 which also serves as a conductor, and a plate-shaped capacitor.
Although the energy transmission means 30 has been described, it may be applied to the peaking capacitor 3 as well, and the same effect as in the above embodiment can be obtained. In addition, an example in which a general shielded coaxial cable is used as the coaxial/energy transmission means is shown, but the present invention is not limited to this. It suffices to have a cable-like structure with the dielectric 23 interposed therebetween, and the same effect as in the above embodiment can be achieved.

【Effect of the invention】

As described above, according to the present invention, the configuration of the laser device is twofold.
One is a power supply/switch part consisting of a high voltage power supply and a switch, the other is a laser oscillation part centered on a discharge part, and a flat plate (conductor) is used to reduce inductance when connecting the two. coaxial energy transmission means, which also serves as a pulse generation capacitor and a connecting conductor and is configured as one circuit component;
Alternatively, since the connection is made via a plate-shaped capacitance/energy transmission means, a circuit with small inductance can be constructed, shortening the rise time of large current pulses and improving laser efficiency. By increasing the number of capacitors and serving both as a capacitor component and a conductor, the device becomes cheaper.

[Brief explanation of the drawing]

Part 1 is a block diagram of a pulsed laser generator using flat plate energy transmission means according to an embodiment of the present invention, Figure 2 is a block diagram of a pulsed laser generator using a coaxial cable, and Figures 3 and 4 are The figure is a block diagram of a pulsed laser transmission device using coaxial/energy transmission means and plate-shaped capacitance/energy transmission means, Figure 5 is a circuit diagram showing an excimer laser and its excitation circuit, and Figure 6 is a conventional pulsed laser. It is a sectional view showing the structure of a generator. In the figure, 1 is a switch, 2 is a pulse generation capacitor, 3 is a peaking capacitor, 4 is a high voltage power supply, 6 is a discharge section, 7A, 7B are energy transmission means, IO is a power supply/switch section, 11 is a laser oscillation section , 20 is a coaxial/energy transmission means, 21 is a core wire, 23 is a dielectric, 24 is a metal jacket, 25A and 25B are flat plates, and 30 is a plate-shaped capacitance/energy transmission means. In addition, in the figures, the same reference numerals indicate the same or equivalent parts.

Claims (3)

[Claims] (1) A power supply/switch unit consisting of a high voltage power supply that applies the high voltage necessary for laser output pulse generation, and a switch connected in parallel to this high voltage power supply to capture the discharge of electrical energy accumulated in the pulse generation capacitor. , a laser oscillation unit having a discharge unit that outputs laser by discharging the energy accumulated in the peaking capacitor that is charged in response to the energy transfer of the pulse generation capacitor;
Energy transmission means for connecting between the high voltage output terminal of the switch section and the pulse generation capacitor terminal of the laser oscillation section and between the ground terminal of the power supply/switch section and the ground terminal of the laser oscillation section. Pulsed laser generator. (2) A power supply/switch unit consisting of a high-voltage power supply that applies the high voltage necessary for laser output pulse generation and a switch that is connected in parallel to this high-voltage power supply and captures the discharge of electrical energy accumulated in the pulse generation capacitor. , a laser oscillation section having a discharging section that outputs a laser by discharging the accumulated energy of a peaking capacitor that is charged in response to energy transfer of the pulse generation capacitor, the pulse generation capacitor, the power supply/switch section, and the laser. A pulsed laser generator comprising a coaxial energy transmission means having a core wire covered with a dielectric material which also serves as a connecting conductor between oscillation parts, and a mantle metal covering the dielectric material. (3) A power supply/switch unit consisting of a high voltage power supply that applies the high voltage necessary for laser output pulse generation and a switch that is connected in parallel to this high voltage power supply and captures the discharge of electrical energy accumulated in the pulse generation capacitor. , a laser oscillation section having a discharge section that outputs laser by discharging the accumulated energy of a peaking capacitor that is charged in response to energy transfer of the pulse generation capacitor, the pulse generation capacitor, the power supply/switch section, and the A pulsed laser generator equipped with a plate-shaped capacitance/energy transmission means that also serves as a connecting conductor between laser oscillation parts and is pressed into contact with a dielectric between flat plates.