DE8419614U1 - Gas laser tube - Google Patents

Description

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Siemens Aktiengesellschaft Our mark

Berlin and Munich · VPA 84 P f 4 7 3 ΠΡ

Process for its manufacture.

The invention relates to a gas laser tube according to the preamble of claim 1. Such a tube is

for example in US-PS 35 55 450 described. 10

In the known laser version there is the optical closure - Brewster window or (decoupling) mirror - in a metallic frame. The metal part is with the closing element via a (hard or glass) solder connected and brazed or welded to the pipe. In this way a hermetic seal is created, however, at the cost of high process temperatures, which improve the optical qualities of the terminating element

or affect less. 20th

Therefore, the cited patent specification already provides for the window or mirror body to both Letting the sides protrude beyond its frame and a thin membrane with a corrugated profile and a large frame To take outside diameter. Such a construction gives the possibility of the optical element only after its To polish the soldering and, if necessary, to coat it, and catches a considerable amount in the subsequent heating processes Part of the thermal voltages. The entire arrangement is but not particularly stable; In particular, the laser power can be caused by mechanical effects that affect the terminating element Set vibrations and / or tilt, remove.

The holder is less sensitive to shock if you convert the optical element into a metallic, thermally matched one Solder the ring washer, place this unit on a metal perforated screen fused to the laser tube and put both Metal parts welded together at the edges (US-PS 37 17 823). This double flange must be used during the Les 1 Lk / 6/18/1984

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Welding, as stated in the cited literature, ensure ^{a temperature drop of 1200 0} C between the welding point and the light-permeable body; both metal plates must therefore be very thin and / or have a large outer diameter. As a result, the entire suspension is not particularly secure against misalignment and / or takes up considerable transverse dimensions and, moreover, is quite expensive, if only because three instead of two vacuum-tight connections have to be made.

The invention is therefore based on the object of providing the optical terminations in a plasma tube of the type mentioned at the beginning to be enclosed in such a way that the arrangement is compact and robust, the closure elements under normal operating conditions can hold in position and also does not require any special manufacturing effort. This task will solved according to the invention by a gas laser tube with the features of claim 1. If in accordance with the claim If the flange and plate are to be "thermally matched", this means that there is one permanent between the two parts gas-tight glass solder connection can be made. Usually this is possible if the flange is in the area of interest Temperature range has a mean coefficient of thermal expansion between 0.9 and 1.2 times the corresponding plate coefficient. A particularly secure connection is established if the flange changes slightly with temperature

stretches as the plate.
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The metal frame designed according to the invention is a rigid part with a correspondingly large wall thickness - of preferably at least 1mm. Nevertheless, their thermal resistance is on the route between the outer edge and the beam passage opening is relatively high because the disc has a meandering profile with rectangular turns disposes. This profile shape increases the path length to a far greater extent than a wave profile, for example,

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As provided in US-PS 35 55 450 for reasons of elasticity is. In this respect, the metal frame can also be relative get small transverse dimensions and requires no additional Änpaßteil that the disk diameter on the Pipe diameter would have to lead back.

The perforated disk itself is relatively easy to manufacture: The meander profile could, for example, be screwed in

or milling ring grooves can be produced. 10

The idea of providing a Brewster window arrangement with concentric grooves is per se from DE-OS 33) 7233 known. The grooves provided there are, however, in the window body itself and only serve as an elastic buffer that absorbs stresses caused by thermal mismatches during operation keep away from the central window area.

Advantageous refinements and developments of the invention are the subject of additional claims.

The proposed solution will now be based on a preferred embodiment shown in the accompanying drawing

example are explained in more detail.
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The figure shows the decoupling side in a side section End of a "sealed off" -C02 laser, which is intended for some 1OW output power and for example

could be used in medicine. .30

,,This. The pipe end contains a metal cylinder 1, a perforated disc 2 and a mirror body 3.

The mirror body is inside with a dielectric 35 ^; Mehücfachschicht 4 coated, which is partially transparent to a wavelength of 10.6um. The body itself consists of zinc selenide, which practically does not absorb in this wavelength range. For the disc, a Ni ^ gFe ^ ration is chosen, which is thermally adapted to ZnSe. the

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Disk has a beam passage opening 5, ^ n is the mirror body is inserted with both sides projecting base and alternately in both discs' ⁴ "pages brought in annular grooves 6, the grooves are dimensioned so that the socket everywhere has a minimum wall thickness of at least 1mm. In In the area of the opening and the outer edge, the disk ends in a web 7, 8 pointing away from the other pipe end .

The pipe termination is produced as follows: First, the ZnSe body is soldered to the metal disk using a stable or crystallizing glass solder, which is either a powder or a pre-pressed and sintered form. Then the two base surfaces of the body are polished and the inner surface is provided with the necessary dielectric layers. The disc is then placed in the metal cylinder and the welded joint is carried out. Ip. In cases in which the distance between the two disc webs is very small and / or the mirror body must be particularly protected, the end of the laser tube should be enclosed with a copper ring during the welding process, which dissipates part of the heat supplied to the outside. 5 claims
1 figure

Claims (4)

VPA 84 P H730E 1. Gas laser tube with the following features: 1) it is at both ends with an optical each Element sealed vacuum-tight; 2) at least one of the two elements contains one Flange (2) and a body (end plate 3); 3) the flange a) is made of metal, b) has the shape of a disk with a central opening (beam passage opening 5) and a Profile that is several, immediately following one another and alternating after one of the two Flange side directional turns contains, and c) is connected to the gas laser tube (1); 4) the end plate (3) a) consists of one: transparent to the laser radiation Material, b) has the shape of a plate, c) is inserted into the beam passage opening (5) and connected to the flange (2) using a glass solder (9) g bound and d) protrudes in the direction of the plate normal on both sides over the tangantial plane of the flange (2);
characterized in that - the flange (2) 3d) consists of a metal thermally adapted to the material of the end plate (3), e) is rigid, f) a meander profile formed from right-angled turns has and g) is inserted into the gas laser tube (1). 2 * pipe according to claim 1, characterized in that that the flange (2) has a wall thickness of at least 1mm. I ·. «Ft · C · · · C - 6 - VPA P J 4 7 3 OE 3. Tube according to claim 1 or 2, characterized e i c. h η et that the flange (2) of the end plate (3) and the gas laser tube (1) each with one of the other Pipe end facing web (7> 8) and connected to the two parts in the area of the free web ends is. 4. Tube according to one of claims 1 to 3, characterized marked, leave the end plate made of ZnSe and the flange (2) made of Ni4ßFe52.