JPH02275686A - Gas discharge laser - Google Patents

Abstract

PURPOSE: To freely detach respectively elements in a frame by detaching a side plate and to facilitate maintenance, repair, and adjustment by mounting optical elements on support bases provided on both the sides of a gas discharge chamber through vibration stopper members in a frame which contains those elements and gas discharge chamber. CONSTITUTION: The two support bases 52 and 54 for the optical elements are supported individually on lateral support bases 46 and 46' to the vibration stopper members 56 and 56' by the frame, i.e., independently of a housing 16 containing the gas discharge chamber supported individually by providing vibration stoppers on the lateral support bases 48 and 48'. Consequently, relative adjustment between the support bases 52 and 54 can be secured so that they can accurately be reproduced on those support bases without spoiling adjustment of a laser device including repair that will possibly be needed for the gas discharge chamber by making the side plate 50 detachable. Consequently, the operation and adjustment are facilitated and a beam from a laser system can be taken out for a long period.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a gas discharge laser having a frame in which a gas discharge chamber and an optical element forming a laser resonator are arranged.

[Prior Art] Industrial gas discharge lasers supply a laser beam with the desired power over a long period of time, operate reliably,
Furthermore, it is necessary that maintenance is easy, that adjustment is simple and safe, and that access for adjustment is easy.

[Problems to be Solved by the Invention] The present invention proposes improvements to gas discharge laser devices in relation to the above points. Furthermore, the present invention addresses the problem of improving a gas discharge laser, particularly an excimer laser, in such a way that it is easy to operate and adjust, and the beam from the laser system can be extracted for a long period of time.

[Means and effects for solving the problem] According to the present invention, the above problem is achieved by supporting the frame, and
The solution is to provide supports for the optical elements that are rigidly connected to each other in the direction of the laser beam on each side of the gas discharge chamber.

The invention therefore allows gas discharge laser devices, particularly excimer laser devices, to be reset with a small number of operations so that the laser beam can be optically guided from one side or the other of the elongated laser device.

According to the invention, supports are provided on each side of the gas discharge chamber, which are rigidly coupled to each other and on which are mounted the optical elements that form the laser resonator and influence the beam characteristics. That is, the optical elements are each mounted on a support. When reversing the direction of the laser beam, it is only necessary to change the optical elements on the support. This is done through modules. The supports arranged on both sides of the gas discharge chamber can be firmly connected to each other even when the optical elements on these supports are replaced, so that the adjustment is essentially maintained.

A further advantageous refinement of the invention is that the gas discharge chamber is surrounded by an electromagnetically shielded housing containing the above-mentioned support and the optical element arranged on the support. Thus, apart from the external sheet metal casing, the laser device has an additional internal shielding for the gas discharge chamber, which is considered the main source of electromagnetic interference radiation. Therefore, according to this invention,
Other components of the laser, in particular the electronic control unit, etc., are protected from electromagnetic interference radiation, as interference radiation is shielded within the frame of the laser itself.

In a further advantageous refinement of the gas discharge laser device according to the invention, the gas discharge chamber and the support for the optical element are each supported separately from one another on the frame by respective steady rest means.

Another refinement of the invention is the provision of side plates extending parallel to the direction of the laser beam on the outside of the frame and attachably fixed to the supports in order to provide a rigid connection between the supports. The above-mentioned improvements in the gas discharge laser device make it possible to repair or replace the gas discharge chamber without disturbing the adjustment of the optical elements. That is, after changing the gas discharge chamber, the optical elements forming the laser resonator and confining the laser beam need to be readjusted to -1i19.

[Example] The present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 shows an excimer laser device 1 according to an embodiment of the present invention.
FIG. 2 is a perspective view showing the overall configuration of 0. The structure and operation of such lasers are well known and need no further explanation. The laser device 10 has a cross-section hollow frame 12 in which the individual components of the laser are accommodated. The frame 12 forms an elongated parallelepiped with edge members. The axis of the laser beam is indicated by reference numeral 14.

The laser beam is generated in a known manner in a gas discharge chamber arranged in the housing 16 and does not need to be illustrated in detail. Gas discharge chambers and related components are also known. The housing 16 is made of electrically conductive material and therefore provides complete electromagnetic shielding of the gas discharge chamber and associated electrical components.

The frame 12 is entirely coated with a metal coating 18.

A plurality of doors 20 are provided on one long side surface of the parallelepiped frame 12. Maintenance.

For repair and adjustment operations, all assemblies of the laser device are accessible on the side provided with the door 20. The laser device 10 includes an air supply port 2 as is known in the art.
2 and an air outlet 24 are provided.

The laser device according to the present invention is configured in detail as follows.

The input module 26 includes a gas valve block with associated connectors. In addition, the input module 26 has an optical waveguide connector to the main computer disposed externally, ie, outside the frame 12. In addition, the input module 26 includes a mains power source, a remote control device, an associated gas purifier power source and cooling water connectors located outside the frame 12. All coupling lines for electricity, gas, optical waveguides, cooling water, etc. are connected to a vacuum pump module 28 adjacent to a six-person module 26 located at the bottom right 25 of the laser device. . An activated carbon filter 30 is provided on the removable base plate 27. The vacuum pump 32 is mounted on rubber legs to prevent vibration. The vacuum pump module 28 can be easily pulled out on the base plate 27 for maintenance work.

The main unit module 34 is retractably disposed approximately centrally at the bottom of the frame 12 after the associated door 20 is opened. To this end, the main unit module 34:
It is supported on laterally disposed telescoping rails. There is no separate direct connection line between the main unit module 34 and the external coupling.

A control module 36 is similarly arranged above the main unit module 34 so as to be retractable from the frame 12. Control module 36 controls the laser power supply.

The heat exchanger module 38 is also retractably disposed at the bottom right portion. A feature of the laser device shown in FIG. 1 is that it has an internal water circulation system, ie a water circulation system that circulates within the laser itself and in particular cools the gas discharge chamber. The coolant consists of water, corrosion inhibitor and chrycerol as freezing point lowering agent. In the pump 40 with a heat exchanger, the heat taken up in the internal circulation system is released into the external circulation system and conducted outside the laser device. The internal oil circulation system for cooling, especially for thyratron cooling, is
The heat exchanger passes through the pump 42, and the pump 42 is also provided with a heat exchanger. In this case as well, the accumulated heat is transported by the pump 42 to the external circuit.

Above the supply unit of the laser device described above, the frame 12 has two longitudinal columns 44 (only the front one of the two longitudinal columns is shown in FIG. 1). On the transverse struts 46, 46', 48, 48' there are five assemblies arranged in the upper part of the frame 12, which will be explained in more detail later. The side plate 50 extends over substantially the entire front side of the laser device and joins the two supports 52, 54, as will be explained in more detail below. The support stand 52.54 is
a gas discharge chamber, i.e. a housing 16 containing the gas discharge chamber;
are placed on both sides.

The side plate 50 is provided only on the front side of the laser device 1o shown in FIG.

A feature of the laser device according to the invention is that two laser beams in opposite directions on the beam optical axis 14 can be taken out from the laser arbitrarily without changing the position of the frame 12. For this purpose, it is only necessary to alternate each optical element 58.60 on the support 52.54. These optical elements form a laser cavity in a known manner, ie include beam-limiting elements, such as reflectors, coupling mirrors and laser optical gratings, in a known manner. These details are known to those concerned.

The laser beam generated in the gas discharge chamber within the housing 16 passes through sliding openings 62 on both sides of the housing 16 .

In the structure shown in FIG. 1, the optical element 58 shown in particular on the left side is provided with a reflecting prism and a wavelength selection grating. The laser beam exits the laser device to the right along the beam axis.

In order to arbitrarily reverse the direction of the laser beam here, the invention provides two supports 52, 54 for the optical elements.
Place each steady rest member 5 on the horizontal support stand 46 and 46'.
6.56' by means of a frame (see Figure 3) accommodates the gas discharge chambers supported separately, i.e. with steady rests on lateral supports 48 and 48'; The housing 16 is supported independently of the housing 16.

The important point here is that the relative adjustment between the supports 52, 54 is made possible by the removal of the side plate 50, and that the adjustment of the laser device is not impaired after subsequent modification or reset of the laser device, including any repairs that may occur to the gas discharge chamber. The support stand 52.
It is possible to ensure accurate reproduction again on the optical system frame (FIG. 3) that supports 54 or on these supports. The support pedestal 52,54 may be integrated with the optical system frame. The optical system frame 74 (FIG. 3) has a substantially C-shaped shape in horizontal section. The optical system frames 74 are each mounted separately on the steady rest members 56, 56'. In the installed state, the side plate 50 closes the open side of the C-shaped optical system frame, so that the closed rectangle is held dimensionally stable. Details of the optical system frame and its cooperation with the side plate 50 are shown in FIG.

The flexible steel pipe of the gas supply system passing through the frame 12 is
This is a corrugated steel hose with a steel pleated exterior. Therefore, mechanical vibrations are not transmitted.

The electrical cabling of the laser device is such that, as described above, one cable harness can be used to emit the laser beam in two directions. Therefore, the same line portion is connected to the support base 52 on both the left and right sides of the housing 16.
．． 54 and are selectively connected depending on the direction of the laser beam.

In case of working on the gas discharge chamber and replacing it, the side plate 50 is removed by means of four screws 72. The details are shown in FIG. The screw 72 is threaded into the optical system frame 74 through the side plate 50 within the sleeve 78 . The support stands 52 and 54 are placed on the optical system frame 74. The conical guide tube 76, cooperating with a correspondingly formed surface of the sleeve 78, allows the side plate 50 to be reattached to the optical system frame 74 in a precise manner after disassembling the side plate 50, so that the plate The shaped supports 52, 54 are again placed in exactly the same relative position.

In this way, the extension plate 50 can be removed after loosening the four screws 72 (only one is shown in Figure 1), and after this the front side of the housing 16 can also be removed, resulting in access to the gas discharge chamber. become able to. Therefore, the gas discharge chamber is
Can be moved forward from housing 16 for maintenance and repair work (modules 28, 34 described above)
．． 38). For this purpose, the supply lines for the gas discharge chambers are sufficiently long so that they do not have to be removed.

Lifting means 66 are used to pull the gas discharge chamber forward. The lifting means 66 is arranged on both sides of the housing 16 and has rods 68 made of non-conductive material connected to the supply member of the gas discharge chamber at the front and rear sides with respect to the beam direction 14.

The rod 68 (or two parallel rods of the same type) thus passes through the housing 16 on both sides thereof. Hand lever 6 provided on either side
9, the rod 68 is lifted together with the supply member (storage capacitor, etc.) previously separated from the gas discharge chamber, so that the gas discharge chamber is moved forward away from the supply member (as shown in FIG. from the paper). The rod 68 is
It passes through the open lower 0 in the housing 16.

FIG. 3a shows III a -III a ! of FIG. 3b.
FIG. 3 is a vertical cross-sectional view of the optical system frame taken along i.

FIG. 3b is a plan view of the optical system frame 74, i.e., the first
This is a view seen from the top of the figure, with the side plate 50 removed. Third
Figure c is a vertical sectional view of the optical system frame 74 taken along line IIIc-IIIc in Figure 3b, with the side plate 50
is shown removed.

As can be seen from FIGS. 3a to 3c, the optical system frame 74 has a horizontal cross-section (i.e., corresponding to the top view of FIG. 3b) that is generally in the shape of a °C or °U°. The support stands 52, 54 are integrated with the optical system frame 74,
6. The terms "horizontal" and "vertical" above refer to the upright operating position of the laser as shown in FIG.

As is particularly clear from FIG. 3b, the side plate 50 is used to open the optical system frame in the mounted state. 11 is closed, the entire optical system frame has a rectangular shape, and therefore has an extremely stable shape dimensionally. It is also clear from FIG. 3b that the optics frame 74, closed by the side plates 50, surrounds the entire circumference of the housing 16 of the gas discharge chamber. One long side of the rectangle is formed by the side plate 50, and the opposite side is formed by a support 74'. Although the support 74' cannot be removed, two long sides of the rectangle of the optical system frame 74 are formed.
It is removably connected to the two short sides.

The other elements shown in Figures 3a to 3c have already been described above. The short sides of the rectangular optical system frame 74 are supported by steady rest members 56 and 56', respectively.

FIG. 4 is a detailed view showing the support of the housing 16 for the gas discharge chamber on the transverse supports 48 and the longitudinal columns 44 with steady rests.

The lateral supports or beams 48.48' have two approximately
It is made by combining individual U”-shaped parts.2
The two ゛U゛U゛-shaped elements engage with each other and surround a steady rest element 49, 49' made of elastic material. As a result, the housing 16 with the gas discharge chamber
Mechanically separated from other elements of the laser device.

Such a separation is particularly advantageous since, in general, the gas circulation fans normally provided in the gas discharge chamber are unbalanced and cause mechanical vibrations. Mechanical stimulation can also occur during gas discharge in the gas discharge chamber. The structure shown in FIG. 4 prevents the above mechanical stimulation from being transmitted to the laser and other elements.

[Effects of the Invention] According to the present invention, the optical elements of the laser device can be mounted on supports provided on both sides of the gas discharge chamber through steady rest members within a frame that accommodates these elements and the gas discharge chamber. This makes it easy to change the direction of the laser device, and since each element in the frame can be taken out by removing the side plates, maintenance, repair, and adjustment are easy, and mechanical vibrations are not transmitted.

[Brief explanation of drawings]

Figure 1 is a schematic diagram of the entire gas discharge laser device seen from the side; Figure 2 is a sectional view taken along line II-II in Figure 1; Figures 3a, 3b, and 3c. 4 is a detailed view of the optical system frame, and FIG. 4 is a detailed view of the steady rest support. lO...Excimer laser 12...Frame 14...Laser beam axis 16...Housing 18...Metal cover 2
0... Door 26... Human power module 27... Board 28... Vacuum pump module 34... Main unit module 36... Control module 38... Heat exchanger module 49.49'... - Steady rest member 50...Side plate 52.54...Support stand 56.56'... Steady rest member

Claims (6)

[Claims] (1) In a gas discharge laser having a frame 12 in which a gas discharge chamber and optical elements 58, 60 forming a laser resonator are disposed, the frame 12 is supported by a steady rest and is rigidly attached to each other. The optical elements 58, 60 to be coupled
A gas discharge laser, characterized in that supports 52, 54 for use in the gas discharge chamber are provided in the direction 14 of the laser beam on each side of the gas discharge chamber. (2) The gas discharge chamber is surrounded by an electromagnetic shielding housing 16 that does not contain the support bases 52, 54 and the optical elements 58, 60 disposed on these support bases. The gas discharge laser according to item 1. (3) Support stand 5 for gas discharge chamber and optical elements 58, 60
2, 54 are steady rest means 56, 56', 4, respectively.
3. Gas discharge laser according to claim 1, characterized in that they are supported separately from each other on the frame 12 by means 9, 49'. (4) In order to firmly connect the supports 52 and 54, a side plate 50 is provided which extends parallel to the beam direction 14 on the outside of the frame 12 and is detachably attached to the support or optical system frame 74. A gas discharge laser according to any one of claims 1 to 3. (5) The gas discharge laser according to any one of claims 1 to 4, wherein the support stands 52 and 54 are formed into plate shapes. (6) The supply and control elements of the laser are each arranged in modules 26, 28, 34, 36, 38, each individually removably guided in the frame 12 of the laser. The gas discharge laser according to any one of Items 1 to 5.