JPS61199687A - Gas circulation type laser oscillator - Google Patents

Abstract

PURPOSE:To prevent a laser medium gas from getting contamination due to leak into a gas circulation system of lubricant oil by a method wherein the timing gear and the bearing of a Roots blower are constituted of ceramic material so that the need of lubrication of timing gear chamber inside the Roots blower may be eliminated. CONSTITUTION:At the beginning of operation, an electromagnetic valve 22 is closed and a vacuum pump 10 is started, for exhaust which continues until a pressure level of approximately 0.01Torr is attained in a gas circulation system including a discharge tube 1 and in a timing gear chamber 13. Next, a cylinder main valve 23 and the electromagnetic valve 22 are opened, for the introduction of a laser medium gas from a gas cylinder 9 into the gas circulation system and the timing gear chamber 13, which continues until a prescribed pressure level is attained. A process follows wherein the cylinder main valve 23 and the electromagnetic valve 22 are closed, a driving motor 20 is started to drive a Roots blower 8 for the circulation of the laser medium gas, and discharge electrodes 11, 12 are activated for the oscillation of laser, and then the laser is amplified by means of optical resonance to be outputted via a partial reflection mirror 3. With a timing gear 14 and a bearing 15 supporting the shaft 21 of the timing gear 14 being made of an abrasion-proof and heat-resisting ceramic material, no heat-caused size or abrasion is expected to occur.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to preventing contamination of a laser medium gas applied to the inside of a resonator in a gas circulation type laser oscillation device using a roots blower as a gas pumping means.

[Conventional technology]

FIG. 2 is a configuration diagram showing a conventional gas circulation type laser oscillation device. In the figure, (1) is the discharge tube, (2) is the total reflection mirror, (3) is the partial reflection mirror, (4 is the gas inlet, (5) is the
) is the gas outlet, (6) is the DC power supply, (7) is the gas cooler, and (8) is the roots prower. Gas outlet (
5), circulate through the gas cooler (7). (9) is a laser gas cylinder for supplying a new laser medium gas, α[ is a vacuum pump, υ is a cathode, and α2 is an anode.

For CO, laser, gas inlet (41) and gas outlet (5)
A discharge made from a cylindrical glass tube with a
(11U, a cathode 0υ and an anode Q2+, which are discharge electrodes, are installed near the gas inlet (4) and outlet (5), and a DC power supply (6) is applied between them. Also, the discharge tube (1)
Inside, CO*t- is supplied from the gas cylinder (9).
The containing laser medium gas is circulated in a closed loop from the roots proar (8)K via the gas cooler (7). The vacuum pump a1 is used to exhaust impure gas from the closed-loop gas circulation system at the initial stage of operation.

Next, the operation will be explained. While flowing through the discharge tube (1), the laser medium gas passes through the discharge electrodes α11. (Excited by a discharge between 13 and CO, in the case of a laser, CO.

It emits light with a wavelength of 10.6 μm, which is unique to gas molecules. This is amplified by an optical resonator that is installed in the leak of the discharge tube (1) and consists of a total reflection mirror (2) and a partial reflection mirror (3), and the laser beam is emitted from the partial reflection mirror (3) side. It works to extract light.

The temperature of this laser medium gas increases due to the discharge energy, and the oscillation efficiency rapidly decreases due to the temperature increase.
), (7), and in order to make the entire device more compact, the gas flow velocity in the discharge tube (1) was reduced to 200 m.
/S. For this reason, a Roots Prower (8) has recently been used for circulating and pumping the laser medium gas.

The Roots Prower (8) normally rotates cocoon-shaped rotors in reverse synchronization with each other to force feed, and this synchronization is performed via a timing gear.

[Problem that the invention seeks to solve]

Since the conventional gas circulation type laser oscillation device is configured as described above, the timing gear chamber, which consists of the timing gear and bearings of the Roots Prower that rotates at high speed, must be lubricated with lubricating oil. Lubricating oil particles and the like leak into the gas circulation system during operation and contaminate the laser medium gas, shortening the gas life and reducing laser output. Further, there was a problem in that the fine particles adhered to the reflecting mirror of the resonator and received laser light, causing a temperature rise, and the reflecting mirror was damaged due to the temperature rise.

This invention was made to solve the above-mentioned problems, and eliminates the need for lubrication of the timing gear chamber in the Roots Prower, thereby preventing contamination of the laser medium gas due to lubricating oil leaking into the gas circulation path. 〇 [Means for solving the problem] The gas according to the present invention The circulating laser oscillation device is characterized in that the timing gear and bearing of the Roots Prower are made of a ceramic material that is resistant to heat and has wear resistance.

[Effect]

In the gas circulation type laser oscillation device according to the present invention, the timing gear and its bearing for synchronizing the rotation of the rotors that rotate in opposite directions of the Roots Prower are made of ceramic material, so the wear resistance (hardness) of the ceramic material
It also has excellent heat resistance and fully demonstrates its function as a timing gear and bearing smoker without the use of lubricating oil.

Therefore, lubricating oil will not leak into the gas circulation system.
Contamination of the laser medium gas can be significantly reduced.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

In FIG. 1, a discharge tube (1) and a reflecting mirror (2).

(3), a DC power source for discharge (6), an optical resonator consisting of discharge electrodes αυ and α2, a roots prower (8), and a gas cooler (7).
), (7), a gas circulation system path consisting of a gas inlet (41) and an outlet (5), supply of new laser medium gas by gas cylinder (9) K, and discharge of impure gas at the beginning of continuous operation by vacuum pump α1, It is constructed in the same manner as the conventional device and operates in the same manner.Next, in the Roots blower according to the present invention (81, Ql is a timing gear chamber connected to the Roots blower main body, (141 is a timing gear made of a ceramic material, and aS is a ceramic material. αG is the two cocoon-shaped rotors that rotate in opposite directions, the fin is the discharge port, Ql is the suction port, ■ is the coupling, the crest is the Roots blower drive motor, (21) is the rotating shaft, and the mouth is the solenoid valve. C (c) is the main valve of cylinder (9).

Roots Proa (8) quadruple (+hl is shaft Qυ
In addition to the shaft υ which is rotatably driven by the II!h motor ■ and is connected to the rotor α61K, it is connected to the other rotor (not shown). Both shafts are in the timing gear chamber a
Both rotors (161 are connected to (1
They are rotated in opposite directions to circulate and pump the laser medium gas.

Next, to explain the operation, at the beginning of zero operation, the solenoid valve @ is closed and the vacuum pump (IG) is activated, and the gas pressure in the gas circulation system including the discharge tube (1) and the timing gear chamber (13) is , 0.0.0 Torr.Next, open the cylinder main valve (c) and solenoid valve (c) to supply the laser medium gas from the gas cylinder (9) to the gas circulation path and timing gear chamber a3. , a predetermined pressure (50 to 10
(approximately 0 Torr). After that, the cylinder main valve e
31 and the solenoid valve ■ are closed, and the drive motor is used to fully drive the cylinder tube blower (8) to circulate the laser medium gas. The laser light is excited by the discharge electrode α1+eQa, and is amplified by optical resonance. The laser beam is outputted to the outside via a partially reflecting mirror (3). Here, the timing gear (14
and the bearing +151 that supports the shaft ant are made of abrasion-resistant and heat-resistant ceramic material, so there is no need to use lubricating oil like in the past to prevent seizure or excitation. It will never occur. Therefore, there is no fear of lubricating oil leakage, etc., and only clean laser medium gas is pumped through the gas circulation system, so the gas life can be extended and the laser output can be stabilized at 1/C414.

〔Effect of the invention〕

As described above, according to the present invention, since the timing gear and the bearing are made of ceramic material, contamination of the laser medium gas does not occur, the life of the laser medium gas is extended, and stable laser output is obtained. Moreover, deterioration and damage to optical components can be prevented.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a gas circulation type laser oscillation device according to an embodiment of this oscillator #4, and FIG. 2 is a block diagram showing a conventional system. In the figure, (1) is a discharge tube, (7) is a gas cooler, (
8) is roots blower, α3 is timing gear chamber, <14
1 is the timing gear, (151 is the bearing, ae is the rotor, (Lη is the discharge port, (18 is the suction port, ■ is the motor,
Qυ is the shaft. In addition, in the figures, the same reference numerals indicate the same or corresponding parts. Agent Patent Attorney Sanro Kimura Figure 1 Figure 2

Claims (2)

[Claims] (1) A gas circulation type laser oscillation device in which a roots blower circulates laser medium gas in a closed loop to an excitation part within a resonator, wherein a timing gear of the roots blower is made of a ceramic material. (2) The gas circulation type laser oscillation device according to claim 1, wherein the bearing of the Roots blower is made of a ceramic material.