JPH0278285A - Microwave laser device - Google Patents

Abstract

PURPOSE:To improve a laser device in performance at a low cost and to make it compact by a method wherein at least two or more microwave power sources are provided, and they are successively staggered in oscillation phase in order to make a laser output uniform. CONSTITUTION:Two or more microwave power sources, at least, are provided, and a corresponding discharge tube 1 is inserted into two or more microwave waveguide tube reaction tubes 2. And, the microwave glow discharge 4 is formed inside the discharge tube 1 through an incident microwave 3. The discharges are successively staggered in phase by a certain angle, the laser medium inside an optical resonator composed of mirrors 9a and 9b is made constant in density at a laser upper level, so that a uniform laser output can be obtained. And, the microwave 3 excited by a usual alternate power. source can be converted into laser rays adapted for the industry. By this setup, a microwave laser device, which is available in the general industry, high in performance, compact, and low in cost, can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a microwave laser device that performs microwave discharge excitation.

(Prior art) Generally, in order to obtain laser oscillation, it is necessary to generate a spatially uniform discharge in a laser medium. In particular, when microwaves are used for discharge excitation, the discharge uniformity is 1q. In addition, there was a problem in that the microwave generator was large and expensive.

Furthermore, what is required for lasers for processing steel, automobiles, etc. is a continuous or rectangular wave pulse of up to about 1KH7 as shown in FIG. 6, and the pulse width and pulse interval are variable.

(Problem to be solved by the invention) However, the core of a normal microwave oscillator is a magnetron, but in order to operate the magnetron in a manner that satisfies the above-mentioned requirements, it is difficult to operate the magnetron to meet the above requirements. The requirements were excessive and there were problems in terms of practicality. Therefore,
At present, a microwave laser device for use in the skin industry has not been put to practical use.

Therefore, there has been a strong desire to develop a technique for achieving uniformity in discharge and direct current laser light, which has been impossible with conventional microwave discharge techniques.

The present invention was proposed to solve the above problems, and its purpose is to provide a high-performance, compact, and low-profile microwave laser device that can be used for general industrial use.

[Structure of the Invention] (Means for Solving the Problem) The invention as claimed in claim 1 is a vacuum container in which a laser medium gas is sealed at low gas pressure, and an excitation part and L, and a microwave disposed outside the vacuum container are provided. A microwave laser device that excites the laser medium gas by supplying microwaves from a power source, characterized in that at least two or more microwave power sources are used, and the oscillation phase of each microwave power source is sequentially shifted. is.

In addition, the invention of claim 2 is characterized in that a laser medium gas is sealed in a vacuum container at low gas pressure, and this gas is used for laser emission (circulated in the crotch area, and microwaves are supplied from an external microwave power source). In the microwave laser device that excites the laser medium gas, the microwave discharge excitation part and the laser emitting station are separately located, and the microwave discharge excitation part is disposed upstream of the laser emitting part. When L is the circulation speed of the laser gas, L is the area where the excited gas exists in the laser oscillation section, and f is the frequency of the microwave power, then v=2L・fx1
/n (n: an integer).

(Function) According to the microwave laser device according to the invention of claim 1,
Since the phase of the microwave is shifted by multiple waveguides in the discharge tube, the microwave energy with a shift in phase is essentially integrated between the tips (crotches), and the gas molecule density at the upper level of the laser is It remains approximately constant.

Further, according to the microwave laser device according to the second aspect of the invention, by circulating the laser gas, the upper level density of the laser C-pulled within the optical resonator can be made substantially constant.

(Example) Hereinafter, an example of the present invention will be specifically described based on FIGS. 1 to 5.

First Embodiment In this embodiment, as shown in FIG. 1, a laser discharge tube 1 made of quartz is filled with laser gas at a pressure of several tens of Horr. Further, the discharge tube 1 is inserted into a plurality of microwave waveguide reaction tubes 2, and the incident microwave 3
The structure is such that a microwave glow discharge 4 is formed therein. Further, the microwave 3 is radiated by a microwave oscillator 5 provided at one end of the microwave waveguide reaction tube 2, and these oscillation operations are performed by a phase shifter 6 connected to the crotch portion 5 of each microwave. Accordingly, the commercial frequency AC voltage is sequentially shifted by θ (-π/(n+1), where n is the number of microwave oscillators). Roughly speaking, a termination section 7 is provided on the other end side of the microwave waveguide reaction tube 2, and this is normally lined with a reflector and connected to the discharge tube 1.
The microwave 3 that has passed through the discharge tube 1 is returned to the discharge tube 1 so that it can be effectively used for glow discharge 4. Further, Brewster windows 8a are provided at both ends of the discharge tube 1.

8b, a total reflection mirror 9a and an output mirror 9b are provided on the outside thereof, and a pair of tips (crotch portions are configured).

In the microwave laser device of this embodiment having such a configuration, the microwave discharges 4 generated in the discharge tube 1 are sequentially shifted in phase by θ, and the phases of the microwave discharges 4 are shifted by θ, and a pair of 5i9
Since the laser upper level density of the laser medium in the optical resonator constituted by a and 9b is constant as a whole, the obtained laser output is also uniform. Furthermore, microwaves excited by a normal AC power source can be converted into laser light suitable for use in general industries such as steel and automobiles. In general, the microwave oscillator does not need to be a special one, and a commercially available microwave oscillator is sufficient, making it possible to obtain a small and low-cost microwave laser device.

■Second Embodiment In this embodiment, as shown in FIG. It is composed of. Further, the laser gas sealed inside is cooled by a heat exchanger 13 and circulated by a blower 14 in the direction of the arrow shown in FIG. Furthermore, microwave energy is supplied to the waveguide reaction section 12b from a microwave oscillator 16 via a waveguide 17.

At this time, the circulation speed V of the laser gas is defined as v=2L・fx1/n (n
; integer). Also, the distance between the discharge excitation section 12 and the laser oscillation tube 11! + and - are also set small enough.

In the microwave laser device of this embodiment having such a configuration, the laser gas discharge-excited in the discharge excitation section 12 is transported from the discharge section by the flow of laser gas and enters the laser oscillation tube 11. Then, as shown in FIG. 3, the laser upper level density moves within the laser oscillation tube 11 with a sinusoidal distribution L, for example, riding the flow.

Therefore, if an integer multiple of a half wavelength enters the laser oscillation tube 11, the total amplitude of the laser upper level molecules here will always be constant, so a constant laser output can be obtained.

Furthermore, in this embodiment, since the discharge excitation section 12 and the laser tube 11 are placed separately, the laser gas is stirred and mixed in the process of being transported from the discharge excitation section 12 to the laser oscillation tube 11. . Therefore, even if the discharge excitation is not uniform in the discharge excitation section 12, it becomes uniform in the radial direction when the excited laser gas enters the oscillation tube 11 of the sea 11.

In this way, according to this embodiment, the total position of the laser upper level molecules inside the laser oscillation tube can be kept constant at all times, so it is possible to obtain an ideal single-mode DC laser output. . Also in this case, microwaves excited by a normal AC power source can be converted into laser light suitable for use in general industries such as steel and automobiles.

■Third Embodiment In this embodiment, as shown in FIG. 4, an output plane mirror 21 is disposed at one end of the laser discharge tube 1, and a total reflection concave mirror 22 and a convex mirror 23 are disposed at the other end. The tip (
The crotch is made up of. Further, a mechanical chopper 24 is disposed between the total reflection concave mirror 22 and the convex mirror 23, and is configured to be rotated by a drive motor 25 in synchronization with a commercial frequency AC voltage. The mechanical chopper 24 is, as shown in FIG. 5, formed by forming a notch 27 in a disk 26 that blocks light.

In the microwave radiation device of this embodiment having such a configuration, when the microwave 3 enters the discharge tube 1, a glow discharge 4 is formed and the laser gas is excited.The light 28 generated at this time is is focused by the convex mirror 23 and becomes 1,
After focusing near the point P in FIG. 4, it is reflected by the copper mirror 22 and follows the original path in the opposite direction, and a part of it is transmitted by the output plane mirror 21, which is the output mirror, and the laser outputs 29. becomes. The remaining light is reflected back to its original state, and optical energy is accumulated, leading to laser oscillation. In order to control the presence or absence of this laser oscillation, a mechanical chopper 24 is provided between the total reflection concave mirror 2 and the convex mirror 23 so that the laser oscillates when the notch 27 comes near the point P. It is configured. Therefore, by controlling the rotation of the drive motor 25, the point P
It is possible to control the closed phase between the light and the path in the
Any output laser light waveform can be obtained according to load requirements.

Note that this embodiment can also be applied to a type of microwave laser device in which a laser medium gas is circulated, as shown in FIG.

In this way, according to this embodiment, by using a simple mechanical chopper, it is possible to output 1q of output laser light with any waveform from direct current operation to pulse operation, so it is suitable for general industrial use. It can be used in a wide range of ways.

[Effects of the Invention] As described above, according to the present invention, at least two or more microwave power sources are used, and the oscillation phase of each microwave power source is sequentially shifted, or the microwave discharge excitation unit and the laser To provide a high-performance, low-order microwave laser device that can be used for general industrial use by simply configuring the head and tail parts to be placed separately and the laser gas to be circulated. I can do it.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a first embodiment of a microwave laser device of the present invention, FIG. 2 is a block diagram showing a second embodiment of the present invention, and FIG. Figure 4 is a configuration diagram showing the third embodiment of the present invention, and Figure 5 is a front view showing the structure of the disk part of the mechanical chopper used in the third embodiment. Figure 6 shows examples of laser light waveforms required for general industrial use. 1...Laser discharge tube, 2...Microwave waveguide reaction tube, 3...Microwave, 4...・Microwave discharge, 5
... Microwave oscillator, 6... Phase shifter, Ba, Bb
... Brewster window, 9a... Total reflection mirror, 9b
... Output mirror, 10 ... Laser light, 11 ... Laser light (limb tube, 12 ... Discharge excitation part, 13 ... Heat exchanger, 14 ... Blower, 16 ... Micro Wave light (crotch part, 17... waveguide, 21... output plane mirror, 22...
... Total reflection concave mirror, 23 ... Convex mirror, 24 ... Mechanical chopper, 25 ... Drive motor, 26 ... Disc,
27... Notch.

Claims (2)

[Claims] (1) A microwave laser device in which a laser medium gas is sealed at low gas pressure in a vacuum container to serve as an excitation section, and microwaves are supplied from an external microwave power source to the excitation section to excite the laser medium gas. A microwave laser device characterized in that at least two or more microwave power sources are used, and the oscillation phase of each microwave power source is sequentially shifted. (2) A laser medium gas is sealed in a vacuum container at low gas pressure, this gas is circulated to the laser oscillation unit, and a microwave is supplied from an external microwave power source to excite the laser medium gas. In the microwave laser device, the microwave discharge excitation part and the laser oscillation part are placed separately,
When the microwave discharge excitation section is arranged upstream of the laser oscillation section, the circulation speed of the laser gas is V, the length of the excitation gas in the laser oscillation section is L, and the frequency of the microwave power is f, A microwave laser device characterized in that the setting is made to satisfy V=2L·fx1/n (n: an integer).