JPS58102582A - Laser oscillator - Google Patents

Abstract

PURPOSE:To facilitate the replacement of only an electrode regardless of an outer tube to which oil and water are attached and to make the electrode compact and inexpensive, by independently disassembling a laser tube and the outer tube. CONSTITUTION:The outer tube 13 is attached to an outer tube supporting tool 22 through an O-ring 21. The laser tube 4 is pushed by an O-ring 9 using a screw to the electrode 24, and hermetically sealing property is obtained. In this way, the expendable electrode 24 can be replaced by loosening the screw 23, and the size of the electrode 24 itself can be made compact. As for the material for the electrode 24, a material whose surface oxidation is less such as copper and stainless steel is suitable for the purpose since a heat resistance and arc resistance are required.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a laser oscillator, such as a Co2 laser oscillator, in which laser gas is flowed at high speed, electrodes are provided that are exposed to the gas flow, and a plasma state is created between the electrodes to oscillate the laser. .

First, a conventional laser oscillator will be explained.

FIG. 1 is a cross-sectional front view of a gas laser oscillator in which a glass standard round tube is used for the laser tube portion of the gas laser oscillator.

In a gas laser oscillator, an electrode 3.3' is usually provided between the total reflection mirror 1 and the semi-transmission output mirror 2, and a laser tube 4 made of a glass standard round tube made of an electrically insulating material is connected between the electrodes 3.3' and 3.3'. While the laser gas is flowing from the gas port 6 through the laser tube 4 to the gas outlet 6 at high speed, the electrode 3
A high DC voltage is applied between 3' and a discharge 7 is obtained. This generates laser 8.

As shown in Fig. 1, a method for holding this laser tube 4 on the electrodes 3, 3' with good circularity and cooling while maintaining high airtightness is to machine an O-ring groove in the electrode 3 and attach an O-ring 9, etc. It was common to use In the figure, 1o is a fixture for the total reflection mirror 1, 11 is a fixture for the semi-transmissive output mirror 2, 12 is a holding tool thereof, and 13 is a fixture for cooling the laser tube 4 heated by the discharge 7. This is an outer tube for flowing oil or water 14. 15.16 is cooling oil or water 1
4 entrance and exit.

FIG. 2 shows an example in which the electrode 3 is divided into two parts, a tube support 17 and an electrode 18. In this conventional example, the groove machining for the O-ring e, which was relatively difficult in FIG. 1, is easy, and the airtightness with respect to the outer diameter of the O-ring 9 is particularly improved. However, in this example, since the laser tube 4 comes out in the input direction, a stop portion 20 is usually provided as shown in FIG. 3 to prevent the laser tube 4 from coming out.

The disadvantage of the conventional example shown in FIG. 1 is that the electrodes 3, 3' are discharge surfaces and are worn out, and if used for a long time, the discharge becomes unstable due to oxidation, etc., but in order to replace the laser tube 4. It is necessary to disassemble the outer tube 13 together.

Moreover, the price of the electrode itself is high. Also, in the example in Figure 2,
This disassembly only requires the laser tube 4, but the width of the groove for holding down the QIJ ring 9 remains constant. When the groove width is constant, 0
The cross-sectional shape of the ring is constant, and a glass standard round tube with a large outer diameter error (generally, there is an error of about ±0.8 with an outer diameter of φ30 rrm) cannot be used because airtightness cannot be obtained. .

The present invention allows the laser tube 4 and the outer tube 13 to be disassembled independently, thereby preventing oil and water from adhering to the inner surface of the laser tube 4 (which is directly linked to staining the mirror) due to the disassembly of the outer tube 13. In addition, the electrode 3゜3', which is a consumable item, can be provided at low cost and easily replaced, and a glass standard round tube with large errors can be used by simply cutting it to a certain size without special additional machining. It is an object of the present invention to provide a laser oscillator having a function to equalize the pressure of an O-ring or the like.

One embodiment will be described below. FIG. 4 is a cross-sectional view of the main parts of the laser oscillator according to the present invention.
is attached to the outer tube support 22 via an O-ring 21. Attach the O-ring 9 to the electrode 24 of the laser tube 4 using a screw 23 or the like.
When pressed, airtightness is achieved. Thereby, the electrode 24, which is a consumable item, can be replaced. As the material for the electrode 24, since heat resistance and arc resistance are required, materials with low surface oxidation such as copper and stainless steel are suitable.

Here, the detailed structures of the electrode 24 and the laser tube 4 shown in this embodiment are shown in FIGS.

As shown in FIG.
m. ), φC needs to be larger than φ30.8wn. When this is assembled, a gap T is created by the amount that the outer dimension of the glass tube is larger than the lower limit.
It becomes 29.2mm. ), since the length L of the electrode insertion hole φC1 is the same as that shown in FIG. 6, the gap T in FIG. 6 is reduced to T' by the narrowness of the outer diameter of the glass tube. At this time, if you manage the tightening force of the screw 23 with a torque driver etc., the dimensional tolerance of the laser tube will be large.
Even in the case B, the dimension φC+L of the electrode 24 can be used in common even in the case of the dimensional tolerance rate φD. As a result, the pressing force of the O-ring 9 against the laser tube 4 can be made almost uniform regardless of the variations in the dimensions of the laser tube 4, so that oil and water leakage or cracking of the laser tube is drastically reduced. .

Furthermore, as shown in FIG. 3, the laser passage hole 26 of the electrode 24 is made to have a smaller inner diameter φΣ than υ of the laser tube 4, thereby cutting the bottom of the Gaussian distribution of laser energy.
It is possible to purify the mode. At this time, φF with respect to φF becomes an aperture effect, but as the mode becomes more purified, the power decreases, so it is necessary to determine the diameter of φF as an aperture while checking the mode situation. It must be possible to remove or replace it.

The laser oscillator of the present invention meets the above demands and has the following effects.

(1) Only the electrodes can be easily replaced regardless of the outer tube having oil or water attached.

(2) Separating the electrode, which is a consumable item, from the support function of the laser tube and outer tube makes it smaller and cheaper.

(3) By separating the electrodes, it is possible to use standard commercially available laser tubes with large dimensional variations, and the dimensional variations can be absorbed by the torque with which the electrodes are pushed.

This makes inexpensive laser tubes airtight and resistant to cracking (
Even if the laser tube is somewhat thick, it can be supplied because the O-ring's tightening force is almost uniform, and since it is a standard commercially available material, it can be supplied without special additional machining.

(4) By separating the electrodes, it is possible to provide a low-cost, easily replaceable aperture for mode purification.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional front view of a conventional laser oscillator, and FIG.
The figure is a cross-sectional front view of the peripheral part of the electrode in which a glass tube with the upper limit of dimensional tolerance is used in the same laser oscillator, and FIG. 4...-Glass standard round tube (laser tube), 9.21
...0 ring, 13...outer tube, 22...
...Outer tube support, 23...Screw, 24...
... Electrode, 26 ... Laser passage hole. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2 369- Figure 5 Figure 6

Claims (1)

[Claims] A glass standard round tube is used as the laser wall, and an electrode having an inner diameter smaller than the inner diameter of the glass standard round tube is used as a shaft sealing part and a mode purification aperture of the glass standard round tube, and is placed on the outer periphery of the glass standard round tube. A laser oscillator characterized in that the electrode is detachably attached to an outer tube support supporting a square outer tube.