JPS59125682A - Method for starting high velocity axial flow type gas laser - Google Patents

Abstract

PURPOSE:To obtain the desired laser output by operating only a vacuum pump at the starting time, forming a low velocity laser gas flow state, applying a voltage to each discharge tube to discharge the all tubes, then operating a blower pump to set high speed gas flow state, thereby hardly discharging one side. CONSTITUTION:When a laser is started, gas is supplied from a gas supply unit 15, and gases are flowed in parallel by a rotary pump 14 at a low speed to four discharge tubes 1, 2, 3, 4. In this case, a valve 35 is closed, and a valve 16 is opened. In case of this low speed flow, the flow rate of the gas flowed to the four tubes tend to become uniform, and the discharge starting voltages of the four tubes are equalized. Then, when voltages are respectively applied between the anode 22 and the cathode 26 of the tube 1, between the anode 23 and the cathode 27 of the tube 2, between the anode 24 and the cathode 28 of the tube 3 and between the anode 25 and the cathode 29 of the tube 4 from the wire 18 in the low speed gas flow state, the all tubes 1-4 simultaneously discharge. After these all tubes discharge, the valve 35 is opened, and the valve 16 is closed. Then, the gas flows in the tubes at high speed to obtain the desired laser output.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for starting an axial flow type gas laser device that flows gas at a high flow rate into a plurality of discharge tubes.

High-speed axial flow gas laser U1, Laser Kowa 1. This is a gas laser in which the discharge tube tube axis and the axis of the gas flow direction are the same, and in which laser gas (hereinafter simply referred to as gas) flows at high speed through the first discharge tube in order to achieve high laser output. be. This high-speed axial flow gas laser has a long laser origin length to obtain larger laser output.
The diameter of the laser stone (diameter of the discharge tube) is made smaller in order to suppress the low-order laser oscillation mode. However, since the tube diameter is small and the tube length is long, a high pressure is required in order to cause discharge. Therefore, in a high-speed axial gas laser, the long 1r[
Optically coupled outside the target without using a long discharge tube
By using a discharge tube with several short tube lengths, discharge is performed at a relatively low voltage, and high-output laser light is obtained in the low-order ascending 11i mode.

When using a plurality of discharge tubes in this way, it is necessary to flow gas through these discharge tubes in parallel. In order to make this gas flow at high speed, it is possible to equalize the gas flow in multiple discharge tubes. Therefore, the discharge starting voltage in each discharge tube is different.11) Therefore, it is difficult to obtain a discharge in all discharge tubes, and the phenomenon of single discharge in which discharge occurs only in some discharge tubes often occurs. There was a problem that the desired laser output could not be equated.

It is an object of the present invention to provide a method for starting a high-speed axial flow type gas laser device f6 that solves such problems and allows a single discharge to occur and a desired laser output to be obtained.

The configuration of the present invention includes a plurality of discharge tubes filled with laser gas and connected in series, a blower pump that flows the laser gas into each discharge tube at a high flow rate, and a vacuum pump that serves as an auxiliary pump for the blower pump. In a method for starting an axial flow gas laser device, only the vacuum pump is operated at startup to create a low-speed laser gas flow state t, a voltage is applied to each of the discharge tubes to discharge them all, and then the blower pump is operated. It is characterized by allowing a high-speed gas flow state.

In the present invention, even when gas is caused to flow in parallel to multiple discharge tubes, if the gas flow rate is made low, the variation in the flow rate of gas flowing through each discharge tube (=j) will be reduced, so each discharge and the discharge of each tube will be reduced. The starting point is that the pressures become approximately equal and the single discharge occurs.

That is, in order to obtain a practical high-speed axial flow gas laser that does not cause single discharge, the laser device is set to a low-speed gas flow state only when starting up, and after all discharge tubes have obtained discharge, the high-speed gas flow state is set. That's what I did.

Next, the present invention will be explained in detail using the drawings.

FIG. 1 is a block diagram of a conventional high-speed axial flow gas laser device. In this laser device, four discharge tubes 1, 2, 3.4 are optically connected in series to obtain a large laser output, and each of the discharge tubes 1 to 4 has anodes 22 to 25 and cathodes 26 to 4. A voltage of 7 watts is applied from the power supply 18 to the terminals 29 through the stabilizing resistors 30 to 33.

The resonator of this laser is composed of reflectors w19, 2o, and a roots pump (also called a mechanical booster pump) 13 serves as a blower for making gas flow at full high speed from a gas supply device 15, and as an auxiliary pump for this roots pump 13. A rotary vacuum pump (hereinafter referred to as rotary pump) 14 is used.

When starting up this laser device, first, before operating the Roots pump 13 that causes gas to flow at high speed, the rotary pump 14 is powered by 81° to reduce the pressure at the outlet 21 of the Roots pump. At this time, the pulp 16 of the rotary pump 16 is open. Once the pressure at the outlet 21 of the Roots pump 13 has been reduced, the valve 16 is closed and the Roots pump 13 is turned on and the gas begins to flow at high speed through the discharge pipes 1, 2, 3.4. However, the gas inlets 6 and 7 of the discharge tubes 3 and 2 are close to each other, and the gas inlets 10 of the discharge tubes 3 and 4 are close to each other.
, 11 are in close proximity, and the gas outlets 8 of the discharge tubes 2 and 3
, 9 are close to each other, it is difficult to equalize the flow rate of gas flowing through the four discharge tubes at a heavy speed.
The discharge starting temperature of the discharge tube 1, the pressure is different.

Now, with the gas flowing at high speed, turn on ■1 source 18, and turn on the anodes 22, 23, 24, 25 and the seven cathodes 26 of each discharge tube.
'11 between , 27, 28 and 29 respectively.
, apply pressure. Note that the stabilizing resistors 30, 31, 32 .
33 is connected in series to each anode 22, 23, 24, 25 for each discharge, ? This is also for stably discharging '1'. Since the discharge starting voltages of the four discharge tubes 1 to 4 are different from each other, it is difficult to obtain a discharge in each discharge tube at the same time, and a partial discharge occurs. Once a partial discharge occurs, it will not be discharged forever in a discharge tube that is not discharging for the following reason.

For example, discharge tube l discharges. Assume that the discharge tube 2 does not discharge. In this case, a current flows through the stabilizing resistor 30 of the discharge tube 10, and a current of 113 flows through the stabilizing resistor 31 of the discharge tube 2.

Since no current is flowing, a potential difference is created between the anode 22 and the anode 230, and a discharge occurs between the anode 22 and the anode 23. Then, 'l' (current) flows through the stabilizing resistor 31, and the potential of the anode 23 decreases, and the potential difference between the anode 23 and the cathode 27 becomes smaller than the discharge starting potential difference, so the discharge between the anode 23 and the cathode 27 In this laser device, the desired laser output cannot be obtained until all four discharge tubes are discharged, so if a single discharge occurs, the desired laser output cannot be obtained. This poses a major practical problem.

FIG. 2 is a block diagram of a gas laser device for explaining the present invention in detail. In the figure, the rotary pump 14 is connected to an intake port 34 of the Roots pump 13, and this intake port 34 is provided with a bubble 35. When starting up this laser device, gas is supplied from the gas supply device 15, and the rotary pump 14 releases the gas at low speed into four streams.
Flow in parallel to tubes 1, 2, and 3°4. In this case, valve 35 is closed and valve 16 is open. In the case of this sluggish flow, the current of the gas flowing through the four discharge tubes tends to be uniform, and therefore the discharge starting voltage of the four discharge tubes becomes low.

Therefore, in this low-speed gas flow state, the power supply 18 connects the anode 23 and cathode 26 of discharge tube 1, and the anode 23 and @pole 2 of discharge tube 2.
7. Anode 24 and cathode 28 of discharge tube 3; anode 25 of discharge tube 4;
When voltage l''LL is applied between the cathode 29 and the cathode 29, discharge occurs simultaneously in all the discharge tubes 1 to 4. 13, opens the valve 35, and closes the valve 16, the gas flows at a high rate of 11% and the desired laser output is obtained.

As explained above, according to the present invention, a practical high-speed axial flow type gas laser device υ'1 that can generate d1 single emission T+,' can be realized.
It will be done.

In addition, the high-speed axis 17t and type Kaslaser VC of the present invention are 1
i-ra fast axial flow type coal ridge Gannu laser, high speed 'fQl flow type-c
This includes carbon gas lasers.

[Brief explanation of drawings]

Figure 1 is a block diagram of a conventional high-speed axial flow gas supply device.
FIG. 2 is a block diagram of a cylinder speed axial flow type gas laser device which explains the present invention in detail. In the figure, 1.2, 3.4... discharge tube, 5, 8, 9.12
・・・・・・Gas outlet, 6, 7, 1.0.11...
... Gas inlet, 13- ... Roots pump, 1
4...Rotary pump, 15.''...Gas supply device, 16,17.35...Valve, 18
...Power source, 19.20...Reflector constituting the resonator, 21...Roots pump discharge port, 2
2, 23, 24. 25...Anode, 26, 27
, 28 , 29... cathode, 30, 31° 32
．． 33... Stabilizing resistor, 34... Roots pump intake port.

Claims (1)

[Claims] A high-speed axial flow gas laser device including a plurality of discharge tubes filled with laser gas and connected in series, a blower pump that supplies 3 fU of the laser gas into each discharge tube at a high flow rate, and a vacuum pump serving as an auxiliary pump for the blower pump. In the starting method, at the time of starting, only the front pump is operated to create a low-speed laser gas flow state, a voltage is applied to each of the discharge tubes to discharge them all, and then the blower pump is operated. 1. A method for starting a gastric velocity axial flow gas laser device characterized by bringing the gas into a high-velocity 70-state.