JPS58124284A - Gas laser excited in lateral direction - Google Patents

Abstract

PURPOSE:To obtain a required wind speed and to make the laser device compact, by making the pressure on air blowing side high and the pressure on air exchausting side low by using a principle of jet. CONSTITUTION:A medium gas, which is highly pressurized by a compressor 8, is jetted through a minute opening in a duct connected to a laser head 6. At the contact surface of a duct 11 on the air blowing side and a the laser head 6, the minute opening comprising a slit 12 or hole is provided. The medium gas is sent to the gap between discharge electrode 1 at a supersonic speed or at the required speed under the pressure in the duct 11 on the air blowing side owing to the width of the slit 12. Meanwhile the gas on the exhausting side is sucked by the compressor and the pressure is reduced. The wind speed corresponds to a ratio P1/P2, where P1 is a pressure from the minute opening part provided at the laser head part to the compressor and P2 is a pressure at the laser head part where the discharge electrodes are provided. The magnitudes of P1 and P2 depend on the capacity of the compressor, the size of the minute opening part, and the volume of the duct to which the laser head is connected.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Technical Field of the Invention The present invention relates to the structure of a laterally pumped gas laser that improves laser performance by increasing the wind speed of circulating gas.

(b) Background of the Technology This is a device that generates a discharge in the perpendicular direction to excite the gas in the laser medium to emit laser light.

In order to improve the excitation efficiency, it is necessary to maintain a state of population inversion between the energy levels of the medium gas excited by the discharge.To do this, the medium gas is cooled and the molecules in the lower levels of the gas are It is necessary to lower the density and quickly move the medium gas that has emitted laser light, and for this purpose a method of circulating the medium gas is used.

In this case, molybdenum (M
o) A needle-like electrode made of tungsten (W) or the like is used, with a water-cooled electrode made of copper (Cu) facing each other, and an external power source is used for each needle-like electrode. A discharge current of several hundred mA is flowing.

This figure relates to the configuration of a laser device that blows the Fi medium gas of the present invention to the discharge electrode portion at high speed.

(c) Prior art and problems As a typical example of a horizontally pumped gas laser, Charcoal diagram is a perspective view of a CO laser with a conventional configuration, and Figure 2 is a configuration diagram of the circulation loop of the medium gas in the laser. FIG. 3 is an explanatory diagram of the cross-sectional structure of the discharge electrode portion. In FIG. 1, the discharge electrode 1 is W or M.

An anode and a cathode are arranged in rows with several tens of needle-like electrodes separated by a discharge gap of 2 to 5 crn. This is connected to a high-voltage power supply (not shown) through a current limiting resistor. are connected to form a discharge path.

Next, a laser window 3 is provided on the side surface of the discharge pole part perpendicularly to the discharge pole 1 and the medium gas flow 2, and an optical resonator consisting of a total reflection mirror and a see-through mirror is located on the extension of this window.
Laser output is extracted through a see-through mirror.

In this case, CO, the laser medium gas consists of CO2, nitrogen (N), and helium (He), but during discharge, a current of several hundred mA flows between each needle-shaped L pole. The temperature of the medium gas rises significantly, so the discharge electrodes are placed in a narrow space and a forced air method is used for cooling.

FIG. 3 shows a one-sided structure with a cathode pole 1 installed in the narrow q part, and the discharge pole part requires a flow rate of 20 to 50 m/sec for cooling.

On the other hand, the circulating medium gas needs to be cooled and the halo of gas dissociated during discharge and the reaction products removed, and therefore the medium gas must be passed through a heat exchanger and a gas purifier.

Fig. 2 shows a conventional medium gas circulation loop, in which a blower 4 consisting of an axial fan or a turbo fan blows the medium gas through a gas purifier 5 and passes it through a laser head 6 having discharge poles in the constricted part. The medium gas that is blown and heated while passing through the discharge area is cooled in the heat exchanger 7. However, in this circulation loop, the presence of the heat exchanger 7, the gas purifier 5, and the constricted portion of the discharge electrode all impede the blowing of the media scum, and the flow rate of 20 to 59 m/s in this circulation loop is reduced. In order to obtain this, it is necessary to use a large blower with a diameter of 60 to 80α or a specially designed ^ speed rotation fan, and a large turret. In addition, since the circular blower duct is connected to the rectangular laser head 6, the duct has a complicated shape, and the noise of the large blower is also a problem.

(d) Purpose of BimeiKiori 1 uses the principle of jet flow to obtain the necessary wind speed to create high pressure on the blowing side and low pressure on the exhaust side, and to miniaturize the laser device. It is something.

(e) Structure of the Invention Kieri J uses gas compressor sound instead of a blower, and creates a high pressure by providing a small opening on the blowing side of the discharge pole, and on the other hand, makes the exhaust side of the discharge pole sufficiently loud. By lowering the pressure, the required wind speed can be obtained.

FIG. 4 is a perspective view of a laterally excited gas laser according to the present invention, FIG. 5 is a configuration diagram of a medium gas circulation loop, and FIG. 6 is a cross-sectional structure of a discharge electrode portion.

In the present invention, as shown in Fig. 5, the medium gas circulation loop is composed of a compressor 8, a gas purifier 5, a laser head 6, and a heat exchanger 7. Microscopic duct 1 connected to laser head 6
The main purpose is to emit gas from zero to zero, and the gas purifier 5 may be connected to either the gas side or the low pressure side.

FIG. 4 shows a case where the gas purifier 5 is installed on the high pressure side, and in this embodiment, the heat exchanger is installed adjacent to the compressor 8 in the exhaust side duct 9.

In other words, the medium gas is transferred to the motor 10! The pressure is applied by the compressor 8 driven by the compressor 8, but in this case, unlike the conventional structure, there is no need to use a large diameter duct 11 on the blowing side.

Next, the contact surface of the air-blowing duct 11 with the laser head 6 is provided with a minute opening such as a slit or a hole, and is designed to blow air into the gap between the discharge electrodes.

Figure 6 is a cross-sectional view of an embodiment in which a slit 12 is provided, and the medium gas is blown into the gap between the discharge electrodes 1 at supersonic speed or at a necessary wind speed depending on the width of the slit 12 and the pressure of the duct 11 on the blowing side. The wind side is suctioned and depressurized by a compressor. In other words, the present invention is a book that uses the principle of jet flow to obtain a large speed, and the wind speed is determined by the pressure P between the small opening provided in the laser head and the compressor, and the laser head portion where the discharge pole is present. The pressure P is determined by the ratio PI/P2, and the size of P and P2 depends on the capacity of the compressor, the size of the minute opening, and the volume of the duct to which the laser head is connected. be.

(f) $ Effects of the Invention The present invention was made for the purpose of improving laser performance, and by using a compressor, efficiency can be increased and the diameter of the duct on the blowing side of the discharge electrode can be made larger than in the past. It was not necessary to use all of the components, which made it possible to downsize the device itself.

[Brief explanation of drawings]

Fig. 1 is a perspective view of a carbon dioxide laser to explain a conventional horizontally excited gas laser, Fig. 2 is a medium gas circulation loop, Fig. 3 is a cross-sectional structure of a discharge electrode, and Fig. 4 is a perspective view of a carbon dioxide laser according to the present invention. A perspective view of an embodiment of such a horizontally excited gas laser, FIG. 5 shows a circulation loop of a medium gas according to the present invention, and FIG. 6 shows a cross-sectional structure of a discharge electrode portion. In 1, 1 is a discharge electrode, 2 is a medium gas flow, 4 is a blower, 5 is a gas attenuator, 6 is a laser head, 7 is a heat exchanger, 8 is a compressor, 9 is an exhaust side duct, 11 is the ventilation side duct. 7- Figure 1 Figure 3 = 8 = Figure 4 1'δ 6I21I

Claims (1)

[Claims] In a forced circulation type horizontally excited gas laser, a small opening is provided on the blowing side of the electrode section of the laser head, and a relatively large-diameter exhaust port is provided on the blowing side of the electrode section, and these are connected by a compressor to form a circulation loop. The compressor reduces the pressure on the discharge side of the electrode part from the compressor and creates a high pressure between the small ventilation openings, and with this pressure difference, the circulating gas is locally blown from the small openings to the discharge electrode part for cooling. Characteristics of horizontally pumped gas laser.