JPH0414272A - Laser oscillating equipment - Google Patents

Abstract

PURPOSE:To obtain large output laser light in the state that high laser oscillation efficiency is maintained, by installing a discharge tube extention part in the downstream of laser medium gas flow, which part is constituted by extending a discharge tube by a specified length determined by the pumping life of laser medium gas and the average gas flow velocity. CONSTITUTION:A discharge tube 2 is arranged so as to penetrate a cavity resonator. The length of the tube is extended by a specified length, toward the downstream of laser medium gas flow in the discharge tube from the end portion of the resonator, which specified length is determined by the pumping life tau of medium gas and the average gas flow velocity (upsilon). Hence, in the cavity resonator 1, adequate discharge suitable for laser oscillation is obtained, and the laser medium gas 6 contained in the cavity resonator 1 is utilized for laser oscillation. The laser medium gas contained in the discharge tube extention part 11 outside the cavity resonator is not heated by microwave because said gas exists outside the resonator. Said gas is in the pumping state, and therefore can be effectively used for laser oscillation.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a laser oscillation device that utilizes discharge excited by electromagnetic waves in the microwave region.

[Conventional technology]

An outline of a conventional laser oscillation device using microwaves will be explained with reference to FIG.

In Fig. 3, 1 is a cavity resonator, 2 is a discharge tube made of a dielectric material such as a glass tube that penetrates the cavity resonator and is housed inside the cavity, and both ends of the discharge tube 2 are A total reflection mirror 3 and a partial transmission mirror 4 are arranged to face each other and constitute an optical resonator. A laser medium gas 6 is sealed in a communication tube 5 that communicates the discharge tube 2 with both ends of the discharge tube 2, and this laser medium gas 6 is cooled by a heat exchanger 7 installed in the communication tube 5. It is.

Further, the air is circulated by a blower 8, for example in the direction of the arrow.

9 is a microwave generator, and the microwave output from the microwave generator 9 is transmitted through a waveguide (microwave transmission line) 1.
0 into the cavity resonator 1. Note that the waveguide 10 has specifications suitable for transmitting microwaves output from the microwave generator 9, and the cavity resonator 1 is configured to resonate at the frequency of the microwaves.

That is, in the conventional laser oscillation device, the microwave power output from the microwave generator 9 resonates within the cavity resonator 1 to increase its electric field strength, and the discharge tube 2
Electric discharge occurs within the chamber. The laser medium gas 6 is excited by this discharge, an optical resonance phenomenon occurs between the total reflection mirror 3 and the partial transmission mirror 4, and a laser beam 11 determined by the specifications of the laser medium gas is output.

[Problem to be solved by the invention]

Since the conventional laser oscillation device is configured as described above, there are the following problems with regard to increasing the output of laser light.

That is, in order to obtain high-power laser light, the cavity resonator 1
It is necessary to increase the amount of laser medium gas that can be used for laser oscillation by increasing the microwave power input to the laser oscillator, or by increasing the length of the cavity resonator 1 and the discharge tube 2. While doing so.

(1) If the microwave power input to the cavity resonator 1 is too large, the temperature of the laser medium gas 6 will rise and, for example, in a CO laser oscillator, the oscillation efficiency will decrease, causing the laser beam to become The output may actually decrease.

(2) Also, if the cavity resonator 1 is made too long, the discharge tube 2
Problems such as destabilization of discharge generation within the laser medium and an increase in the temperature of the laser medium gas 6 due to the length of the region heated by microwaves occur.

The oscillation efficiency may decrease, and the laser light output may even decrease as in (1).

(3) In a laser oscillation device in which the cavity resonator 1 is used in a long state, the above-mentioned tendency (11, +21) is remarkable.

The present invention has been made in view of the above problems.

We have solved the problem of 6.Difficulty in obtaining high-output laser light while maintaining high laser oscillation efficiency, which is a drawback of conventional devices. The purpose is to provide a laser oscillation device that can be obtained.

[Means to solve the problem]

That is, the laser oscillation device according to the present invention is as follows.

By minimizing the rise in laser medium gas temperature due to an increase in microwave input and increasing the amount of laser medium gas that can be used for laser oscillation, it is possible to obtain high-output laser light while maintaining high laser oscillation efficiency. The present invention provides a laser oscillation device. That is, two aspects of the present invention include a microwave generator that generates an alternating electric field in the microwave region, and a cavity resonator that receives the microwaves generated by the microwave generator and increases the intensity of the alternating electric field in the microwave region. , a discharge tube that is disposed through the cavity resonator, is filled with a laser medium gas, and generates a discharge by the alternating electric field of the microwave; and one end and the other end of the discharge tube. In a laser oscillation device comprising an optical resonator that reflects light in a predetermined direction to cause resonance, and a communication means for circulating and supplying a laser medium gas to the discharge tube, Laser oscillation characterized in that a discharge tube extension part is provided on the downstream side of the laser medium gas flow, in which the length of the discharge tube is extended by a predetermined length determined by the excitation life of the laser medium gas and the average gas flow velocity. It provides equipment.

[Effect]

In the laser oscillation device of the present invention, the discharge tube is arranged to pass through a cavity resonator that is adjusted to obtain an appropriate discharge suitable for laser oscillation, and the length of the discharge tube is The structure extends from the end of the body resonator to the downstream side of the laser medium gas flow in the discharge tube by a predetermined amount determined by the excitation life of the laser medium gas and the average gas flow velocity.
(1) An appropriate discharge suitable for laser oscillation is obtained within the cavity resonator, and the laser medium gas contained within the cavity resonator is effectively used for laser oscillation. and (2) the laser medium gas contained inside the extended discharge tube outside the cavity resonator is not heated by the microwave because it is outside the cavity resonator, and is in an excited state, so it oscillates as a laser. Therefore, compared to conventional devices, the amount of laser medium gas effective for laser oscillation can be increased without increasing the area where the laser medium gas is heated. High-power laser light can be obtained.

〔Example〕

An embodiment of the laser oscillation device of the present invention will be described with reference to FIG. Components with the same numbers as in FIG. 3 are components having the same functions as those in FIG. 3, so they will be quoted as is and their explanation will be omitted.

In FIG. 1, reference numeral 11 denotes a discharge tube extension, which is a feature of the laser oscillation device of the present invention, and is provided on the downstream side in the flow direction of the laser medium gas and outside the cavity resonator 1.

It is conceivable that the length l of the discharge tube extension is 1, for example, the product τV of the excitation life τ of the laser medium gas and the gas flow velocity V in the discharge tube 2. That is, if the average excitation life of the laser medium gas excited to the laser oscillation effective energy level by the discharge generated in the discharge tube 2 in the cavity resonator 1 is τ, then the discharge tube extension within /=τ×v The laser medium gas contained in the portion 11 is on average above the laser oscillation effective energy level and can be effectively used for laser oscillation.

For example, Coto-laser gas (Co snow, N snow, H
It is said that the excitation life in the case of a mixed gas of
7 seconds), then /=200 kaku.

Figure 2 is an example of test results showing the effects of the present invention.
In the figure, the Δ mark indicates the relationship between the microwave input power (5) and the laser light output (5) when the cavity length of the conventional device is set to (L+/) in order to increase the laser light output. 1, and the mark ◯ shows the result when the length of the cavity resonator remains unchanged and the discharge tube extension 11 is added according to the method of the present invention.

It can be seen that when the microwave input increases, the laser light output intensity according to the conventional method and the laser light output intensity according to the method of the present invention are reversed, indicating that the two methods according to the present invention are effective.

In the laser oscillation device described above, the discharge tube is arranged to pass through the cavity resonator which is adjusted to obtain an appropriate discharge suitable for laser oscillation, and the length of the discharge tube is A discharge tube extension part 1 extends from the resonator end to the downstream side of the laser medium gas flow in the discharge tube by a predetermined amount determined by the excitation life τ of the laser medium gas and the average gas flow velocity V.
1, an appropriate discharge suitable for laser oscillation can be obtained within the cavity resonator 1, and the laser medium gas 6 contained within the cavity resonator 1 is used for laser oscillation. Extended discharge tube extension 1 outside the cavity resonator
Since the laser medium gas 6 contained inside the cavity 1 is outside the cavity resonator, it is not heated by the microwaves and is in an excited state, so it can be effectively used for laser oscillation.

That is, by adopting such a configuration, compared to the conventional device, it is possible to increase the amount of laser medium gas effective for laser oscillation without increasing the area where the laser medium gas 6 is heated. It is possible to obtain laser light.

〔Effect of the invention〕

According to the laser oscillation device of the present invention, when increasing the output laser intensity, the increase in laser medium gas temperature due to an increase in microwave input can be prevented without enlarging the cavity resonator by providing the discharge tube extension. Since it is possible to increase the amount of laser medium gas that can be used for laser oscillation while minimizing the amount, it is possible to obtain high-output laser light while maintaining high laser oscillation efficiency.

[Brief explanation of drawings]

FIG. 1 is a basic configuration diagram of a laser oscillation device according to an embodiment of the present invention, FIG. 2 is a graph showing an example of test results showing the effects of the present invention, and FIG. 3 is a basic configuration diagram of a conventional device. 1...Cavity resonator, 2...Discharge tube, 5...Communication tube. 6...Laser medium gas, 9...Microwave generator. 10... Waveguide (microwave transmission line), 11... Discharge tube extension.

Claims (1)

[Claims] A microwave generator that generates an alternating electric field in the microwave region; a cavity resonator that receives the microwaves generated by the microwave generator and increases the intensity of the alternating electric field in the microwave region; and the cavity resonator. a discharge tube that is placed through the tube, is filled with a laser medium gas, and generates a discharge by the alternating electric field of the microwave, and reflects the laser light in a predetermined direction between one end and the other end of the discharge tube. In the laser oscillation device, the laser oscillation device is equipped with an optical resonator for resonating and a communication means for circulating and supplying a laser medium gas to the discharge tube, in which a downstream side of the laser medium gas flow from an end of the cavity resonator is provided. A laser oscillation device characterized in that a discharge tube extension section is provided on the side thereof, the discharge tube extension section extending the length of the discharge tube by a predetermined length determined by the excitation life of the laser medium gas and the average gas flow velocity.