RU1638962C - Method of tight connection of optical member with pipe of gas laser - Google Patents

Abstract

The invention relates to the construction industry and building materials, to electronic equipment, and can be used in the manufacture of active elements of gas lasers. The purpose of the invention is to increase the yield of suitable products. This is achieved by the fact that before installing the optical element on the end of the tube, create argon pressure in the tube above atmospheric by 0.5-1.5 mm Hg. After installing the optical element, the argon pressure is reduced to 0.5-1.5 mm Hg. less atmospheric pressure. At this pressure, a preliminary heat treatment is carried out. Welding with a focused laser beam is carried out in two stages. On the first, the beam is welded during the first rotation of the beam at a length not exceeding 1/3 of the circumference of the optical element with argon pressure less than atmospheric by about .5 mm Hg, in the second stage, increase the argon pressure to exceeding atmospheric pressure by 0515 mm Hg and weld the remaining part of the circumference of the optical element until it is sealed to the laser tube. This allows you to eliminate its displacement at all stages of sealing, ensuring high quality of products when welding in automatic mode This eliminates the subjective intervention of the operator Will allow the widespread introduction of welding of optical elements with the help of a CO3 laser in serial production, which will increase the reliability of active elements of gas lasers 1 il Ј L-

Description

The invention relates to the construction industry and building materials, to the field of electronic technology and can be used in the manufacture of active elements of gas lasers

The aim of the invention is to increase the yield of products

The drawing shows a device for implementing the method of hermetically connecting an optical element with a gas laser tube.

The protective gas supply device comprises a rotameter 1 connected through

the inlet 2 and outlet 3 pipes of the discharge tube 4 with the rotameter 5 The output nozzle 6 of the rotameter 5 is connected to the central tube 7 of the ejector 8, which contains a side nozzle 9 for introducing high pressure air. A pressure gauge 10 is installed between the outlet pipe 3 of the tube 4 and the rotameter 5. The output unit 11 of the discharge tube 4, together with the optical window 12, is installed in the ring furnace 13. Welding is carried out by the laser beam 14 focused using a lens 16.

The method is carried out as follows.

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The discharge tube 4 is fixed so that the ground surface of the optical assembly 11 is in a horizontal plane. An inert gas (e.g. argon) is supplied through the inlet pipe 2 to the discharge tube, the passage of which is monitored and established by the flowmeter 1 and the pressure gauge 10. For windows with a diameter of 20 mm, they are 10 l / h and 1.0 mm Hg, respectively. The cleaned optical window 12 is mounted on the polished surface of the discharge tube, an ejector 8 is connected, connected through the second rotameter 5 to the outlet pipe 3 of the discharge tube 4.

Argon passage and the degree of discharge in the volume of the discharge tube are monitored by rotameter 5 and manometer 10. For windows with a diameter of 20 mm, they are respectively 10 l / h and 1.0 mm Hg.

Before installing the optical window 12 on the end face of the gas laser tube 4, the internal volume of the discharge tube 4 is filled with argon, which creates an excess pressure in the discharge tube of 0.5-1.5 mm Hg during passage. With an excess of Precise pressure less than 0.5 mm Hg the purge is not effective and moisture may settle on the inner surface of the window 12. At a pressure of more than 1.5 mm Hg the optical window 12 is not held onto the polished surface of the output (optical) assembly 11 due to its own gravity.

After installing the window 12, the pressure of the protective gas in the discharge tube is reduced by using an ejector 8, which creates a vacuum at the outlet pipe 3 of the tube and sets the pressure of the protective gas in the volume of the discharge tube at 0.5-1.5 mm Hg. less atmospheric. In this case, the inert protective gas inflow is carried out through the inlet pipe 2, and the outlet with greater speed using the ejector 8 through another pipe 3 from the side of the brewed window 12. The pressure difference is 0.5-1.5 mm Hg. provides reliable retention of the window 12 mounted on the polished surface during pre-heating and welding. With a pressure difference of less than 0.5 mm Hg keeping the window on the polished surface becomes unreliable and even a slight deviation of the polished surface from the horizontal causes reject during reconciliation due to the displacement of the window. With a pressure difference of more than 1.5 mm Hg Penetration of contaminants from the surrounding area through the contacting surfaces of the window and the polished outlet assembly is possible.

The range of overpressure of the protective gas relative to the ambient pressure (atmospheric) is chosen experimentally and depends on the diameter

and the thickness of the optical element (weight of the optical element). The following range of shielding gas circulation speeds corresponds to this division interval: 0.5 mm Hg. - 5 l / h and 1.5 mmHg 0 15l /

After preliminary heat treatment, the sealing (welding) process is carried out directly by, for example, sequentially passing a focused CO2 laser beam 14 along the edge of the window 12 and the output unit 11. The beam propagation speed during welding is 1-2 mm / s and the window edge is connected to the output the discharge tube assembly occurs almost immediately after

0 start welding. Since 1/3 of the circumference of the welded seam is quite enough (as experiments have shown) to reliably hold the window, therefore, 1/3 of the first revolution of the beam rotation is maintained

5 shielding gas pressure of 0.5-1.5 mm Hg less than atmospheric, and then to prevent the penetration of the products of heat treatment of glass into the discharge tube, increase the pressure

0 shielding gas to a value exceeding 0.5-1.5 mm Hg atmospheres and weld (at the second welding stage) the remaining part of the circumference of the optical window until a tight connection with the tube is obtained.

5 The excess of the protective gas pressure at this stage is less than 0.5 mm Hg. from atmospheric will not provide effective protection of the inner surface of the window, and the excess is greater than

0 at 1.5 mmHg causes molten glass to be blown out at the point of exposure to the laser beam, which leads to marriage.

Example. Tight connection of an optical window with a helium-neon 5th laser tube.

Before installing the window 12 on the end of the tube 4, the argon pressure in it was set — Bgnocb 1 mm Hg above atmospheric (ambient pressure) in the rotameter 5.

0 Then, after installing the window, the gas pressure is reduced. Pressure is controlled by changing the argon circulation rate through the tube in the eaters from 5 to 15 l / h using the ejector 8 (6), through

5 which pass overpressure air.

After installation of the window 12, the ejector 8 is turned on, thereby increasing the rate of argon circulation through the tube 4 to obtain a reduced gas pressure in

tube, approximately 1 mmHg below atmospheric. The assembly 11 is placed in the furnace 13 and the assembly is preheated.

After preliminary heat treatment of the optical unit 11 in the volume of the annular furnace 13 to the annealing temperature of the window material (for LK-4 steel, this temperature is 500 ° C), the window 12 is srapped (welded) using beam 14 of the CO2 laser 15 focused by the lens 16 Moreover, the first third of the revolution (the first stage of welding) is maintained rarefaction in the volume of the discharge tube at the level of 1.0 mm RT.article. for windows with a diameter of 20 mm, then the ejector 8 is turned off and an overpressure of 1.0 mm Hg is established in the discharge tube 4, which is set by the rotameter 5 and monitored by a pressure gauge 10.

(In this mode, the remaining part of the circumference of the optical window 12 is welded (second welding step) until a sealed connection is obtained and the optical assembly 11 is annealed according to the known established mode.

Claims (1)

SUMMARY OF THE INVENTION A method for hermetically connecting an optical element to a gas laser tube by mounting the first one at the end of the tube. heat treating it at the annealing temperature, subsequent welding with a focused laser beam and annealing, moreover, the protective gas is constantly blown through the tube. j t - characterized in that, in order to increase the yield of suitable products, the shielding gas is purged before installing the optical element at a pressure of 0.5--1.5 mm Hg. above atmospheric, before heat treatment, the gas pressure is reduced and maintained during the heat treatment by 0.5-1.5 mm Hg less than atmospheric, and beam welding is carried out in two stages - they are welded during the first revolution of the beam rotation at a length not exceeding 1/3 of the circumference of the optical element at a protective gas pressure of 0.5-1.5 mm Hg less than atmospheric, then increasing the pressure above atmospheric by 0.5-1.5 mm Hg, weld the remaining part of the circumference of the optical element