JP2001298229A - Module type gas laser - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a module type gas laser comprising a tube for housing a gas mixture composed of a laser gas, and a discharge unit removably mounted in the tube. SOLUTION: A discharge unit comprises an elongated electrode plate, an elongated high voltage electrode and an elongated ground electrode. The high voltage electrode and the ground electrode are mounted on the electrode plate with their longitudinal axes substantially parallel and apart from each other, thereby defining a gas discharge gap between the electrodes. The discharge unit is a module type one and can be removably mounted as an integrated unit in the tube, and the discharge electrodes are adjustable each other when the discharge unit is completely removed from the tube.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas discharge laser, and more particularly to an excimer laser, and more particularly to a discharge unit for an excimer laser in which a high voltage is applied to two discharge electrodes. About.

[0002]

BACKGROUND OF THE INVENTION Excimer lasers generate high intensity laser radiation in the ultraviolet spectral range. This makes excimer lasers an important tool, especially for medical and surgical applications, as well as other industrial applications.

An excimer laser is a gas discharge laser,
As the laser gas, a rare gas such as argon and a halide gas such as fluoro (for example, an AF excimer laser), or a gas containing a halide (for example, F ₂ ) is used.

Generally, in an excimer laser, a gas mixture containing an active component and another gas is stably supplied between a pair of elongated electrodes in a laser tube by a fan or the like. The high voltage applied between the two electrodes causes a gas discharge in the discharge gap, which produces short-lived excited state molecules from the active component, the dissociation of which produces the ultraviolet radiation that constitutes the laser radiation. . In current excimer lasers, preionization of laser gas by a preionizer is used to improve the uniformity of gas discharge. Since the used laser gas needs to be regenerated before it can be reused, excimer lasers are generally operated in a pulsed mode of operation, with the fan stably replacing the laser gas in the discharge gap.

[0005] The discharge electrode of an excimer laser is usually arranged in a laser tube.

The housing of an excimer laser generally consists of a metal tube, with the top of the cylindrical wall open. The open upper side is covered by an insulating plate. One of the metal tube and the discharge electrode is grounded. The high voltage is applied to the second discharge electrode via a high voltage duct extending through the insulating plate.

[0007] The width of the discharge gap between the two electrodes must be adjusted very precisely to achieve a uniform gas discharge in the discharge gap.

[0008] The optical axis of the laser beam is formed by an array of two opposing electrodes. The electrodes in the laser tube must be adjusted longitudinally and perpendicular to the optical axis. This must be done very accurately to avoid arcing between the electrodes and to avoid hot spots in the excimer laser beam profile.

In the current excimer laser, a laser tube is first prepared, and then most of the parts constituting the laser are mounted one by one in the tube. In particular, a laser tube usually comprises two parts, for example a main part and a cover. One discharge electrode is attached to the main part of the laser tube and the other is attached to the cover. Thereafter, the main part and the cover are connected and the laser tube is closed. As a result, the discharge electrodes are assembled such that a discharge gap is created between them. The accuracy of the discharge gap is determined by the accuracy of the coupling between the main part of the laser tube and the cover. this is,
Correct adjustment of the discharge electrodes to one another is difficult.

Such an assembly is disclosed in US Pat.
No. 1,258.

In another, more flexible arrangement, the electrodes can be adjusted to one another in a pre-mounted tube. This is done from both sides of the pre-mounted laser tube, usually by gauges located between the electrodes.

[0012]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a laser discharge unit for a modular gas laser, especially for an excimer laser which is easy to handle and powerful.

It is a further object of the present invention to provide a discharge unit for a gas discharge laser in which discharge electrodes can be adjusted accurately and easily in order to form an accurate, uniform and uniform discharge gap. That is.

The above and further objects of the present invention are:
This is achieved by a modular, pre-adjustable gas laser discharge unit that is pre-assembled and pre-adjustable before mounting the discharge unit in the laser tube. These objects include, in particular, an elongated electrode plate, an elongated high voltage electrode, an elongated ground electrode, and an insulator, wherein the high voltage electrode and the ground electrode are both attached to the electrode plate, and the insulator separates the high voltage electrode from the electrode plate. This is achieved by a laser discharge unit that is electrically insulated.

By attaching both the high voltage electrode and the ground electrode to the electrode plate, the electrode plate and the electrodes are formed in a modular discharge unit. This means that the gas discharge gap can be adjusted independently of the mounting of the discharge unit on the laser tube.

Preferably, the laser discharge unit according to the invention further comprises at least one high-voltage duct extending through the electrode plate for supplying a high voltage to the high-voltage electrodes. Preferably, the high voltage duct includes a conductive core connected to the high voltage electrode, and an insulator for electrically insulating the high voltage core and the electrode from the electrode plate. Preferably, a tubular elongated insulator is used to insulate the high voltage core from the electrode plates.

Accordingly, the laser discharge unit according to the invention preferably comprises, as high-voltage duct, a plurality of waveguide-shaped coaxial ducts extending through the electrode plates. Each of these ducts comprises a central conductive core and an insulator element, preferably made of a ceramic material, which electrically insulates the core from the electrode plate. The high voltage electrode is electrically connected to the core of the duct, and the ground electrode is electrically connected to the electrode plate. By means of the coaxial duct, each is reliably insulated from each other.

Preferably, the ducts are each inserted into the electrode plate with a limited tolerance between the insulator element and the respective hole in the electrode plate into which the duct is inserted. as a result,
The duct is fixedly held in a limited position. According to an alternative of the invention, this fixing can be achieved only by means of fixing elements such as bolts or screws or tubes which hold the respective ducts in fixed positions in their holes.

Preferably, a gas tight seal is provided between the duct and the electrode plate. Alternatively, the seal can be provided outside the laser tube, for example at the end of a duct. For practical reasons, it is preferred that the holes in the electrode plate and the duct have a circular cross section. In this case, the gas tight seal is ring-shaped. The holes can have a square, rectangular, oval, oval, or any other cross section. Ducts and gas tight seals will also have corresponding shapes. However, ring-shaped seals have the advantage that they are easier to manufacture and handle, are more reliable, and are less expensive than, for example, rectangular seals. On the other hand, the use of metal seals is preferred because metal seals are more resistant to attack and laser radiation by aggressive laser gases. If a ring is used in this case, a commercially available metal seal can be used.

[0020] Preferably, the laser discharge unit further comprises a sleeve surrounding the core and insulator of each duct. Each sleeve includes an inner end supported by an electrode plate, and a free outer end. Each core preferably includes an inner end connected to the high voltage electrode and a threaded free outer end extending beyond the free end of the sleeve. Screw a nut or other fastening means onto the threaded end,
This presses the sleeve against the electrode plate and tensions the core by pulling it. Those skilled in the art will appreciate that any other structure for securing the duct to the electrode via the core or via the insulator element can be used as well. Preferably, the inner end of the core is connected to the high voltage electrode using a screw, such as a threaded bolt threaded at both ends.

Preferably, the core and insulator of each duct are fixed to each other. This is achieved, for example, by providing a shoulder at the inner end of each core that is pressed against the insulator by the pulled core. Preferably, a seal is provided between the shoulder of each core and the corresponding ceramic insulator. However, it is also possible for the core to include a recess and the shoulder provided on the insulator to be inserted into this recess. Alternatively, the core and insulator can be secured together by different structures.

The preferred discharge unit further comprises a pair of standard corona pre-ionizers, which are a pair of elongated cylindrical pre-ionizers having a conductive core and a tubular insulator surrounding the core. The preionizer extends substantially parallel along both sides of the electrode. The insulator of the preionizer can be Teflon or any suitable insulator, but is preferably a ceramic material. It can also be fluoride. Alternatively, any other type of known play-onizer can be used. A play onizer is not necessary for operating the discharge unit. In fact, excimer lasers were known prior to the invention of the play-onizer. However, the preionizer makes the gas discharge between the high voltage electrode and the ground electrode more homogeneous and therefore more reliable.

The corona-type pre-ionizer can be mounted in the immediate vicinity of the high-voltage electrode, preferably on both longitudinal sides of the surface of the high-voltage electrode facing the ground electrode.

It is another object of the present invention to provide an electrode array for a gas laser, specifically an excimer laser, which minimizes laser gas contamination and therefore extends the life of the laser gas.

Therefore, mounting a shadow plate between the gas discharge gap and the insulator to protect the insulator against laser radiation emitted from the gas discharge gap and against light from the pre-ionizer. Can be.

The shadow plate can be arranged at any position between the gas discharge gap and the insulator element.
For example, it can be located just above the discharge gap on the high voltage electrode or on the high voltage conductor. Preferably, the shadow plate is inserted between the high voltage electrode and the high voltage conductor.

The shadow plate can be flat. However, it is preferred to bend the edge of the shadow plate towards the insulator element. In order to more efficiently protect the insulator, it is preferable to bend the edge of the shadow plate towards the insulator element. Further, it is desirable that the shadow plate be of a flow guiding configuration to assist in guiding the laser gas mixture, typically comprising a laser gas and a buffer gas, into the gas discharge gap.

It is a further object of the present invention to provide a gas laser having a very small size and capable of continuously circulating a gas flow in the gas laser while removing the dust from the gas laser, and a dust removing unit therefor.

Accordingly, a gas laser having a tube as described above has a cylindrical inner wall and comprises circulating means, such as a fan, positioned within the tube to generate a gas flow in the tube passing between the electrodes. Further, the dust removing unit is mounted along the cylindrical inner wall of the pipe so that a bypass flow which is a part of the gas flow in the pipe passes through the dust removing unit.

By allowing only a portion of the gas flow in the laser tube to pass through the dust removal unit, turbulence in the circulating gas is avoided and a continuous gas circulation in the tube during laser operation is provided. Thus, a continuous gas flow is provided in the gas discharge gap between the two electrodes to achieve effective ionization of the laser gas.

Furthermore, the structural size of the gas laser can be reduced compared to prior art designs because the dust removal unit is mounted along the inner cylindrical wall of the tube. In certain preferred embodiments of the present invention, the dedusting unit is mounted directly in the tube and integrated in the tube, providing a compact and operationally efficient gas laser. The centrifugal force of the bypass gas flow toward the inner wall of the cylindrical tube adjoining the dust removal unit helps to effectively place dust particles on this cylindrical wall portion without directing this flow in an undesired direction. As the dust removal unit electrostatically charges the dust particles, they continue to adhere to the cylindrical wall portion of the tube.

[0032] In a preferred embodiment of the invention, the dust removal unit comprises a partition having a substantially circular central section extending substantially parallel to the cylindrical inner wall. The arrangement and design of the bulkheads allows the gas flow to precisely control the bypass flow between the bulkhead and the cylindrical inner wall to remove this bypass flow. For an effective dust removal, it is sufficient to direct only a small part of the total gas stream through the dust removal unit.

The bypass flow has a substantially constant cross section to ensure efficient and uniform dedusting of the bypass flow.
Guided through a mouth portion having a limited orientation with respect to the septum and the cylindrical inner wall. The residual or main gas stream is guided along the side of the bulkhead remote from the inner cylindrical wall. This main gas stream is continuously supplied to the circulation means together with the joined dust-free bypass stream. The circulation means circulates the gas again through the discharge gap and then again through the dust removal unit to split the gas back into a main stream and a bypass stream to be dusted.

The dedusting unit preferably comprises a U-shaped channel extending parallel to the electrodes, this channel having perforated walls so that the bypass flow can pass through the walls of the U-shaped channel. The U-shaped channel can be formed in a small size and can be easily attached to the dust removing unit.
The perforated walls of the U-shaped channel enhance the electrostatic field for electrostatically charging and attaching the dust particles to the inner wall of the tube.

In order to form a non-uniform electric field in the dust removal unit which electrostatically charges the dust particles, a high voltage wire is longitudinally stretched between two adjacent walls of the U-shaped channel to generate a positive high voltage. Can be supplied. Therefore,
As the dust particles in the bypass stream are electrostatically charged and attracted by the grounded cylindrical inner wall of the tube, the bypass stream will be reliably filtered in the dust removal unit.

In order to improve the dust removal efficiency of the bypass flow,
A plurality of U-shaped channels can extend parallel to and along the length of the tube. In addition, high voltage wires can be placed between the walls of one or more U-shaped channels. Thus, the dust particles are electrostatically charged at some locations within the dust removal unit and become trapped along the entire cylindrical inner wall in that area of the dust removal unit. Thereby, the efficiency of the dust removing unit is improved.

In a preferred embodiment of the invention, the gas discharge unit extends along one side of the cylindrical wall, while the dust removal unit extends along the other side of the cylindrical inner wall. By arranging the gas discharge unit in this manner with respect to the dust removal unit, the timing and pressure ratio of the gas flow are controlled so that a sufficiently clean gas flow is supplied to the discharge unit during laser operation. Dust removal effect is achieved. Further, the space within the gas laser tube is operatively used to assemble the components of the laser.

Another object of the present invention is to provide a gas laser comprising a laser optic together with the improved (especially with regard to structural complexity) dust removal unit.

To achieve this object of the present invention, the gas laser comprises the tube, the tube having a first end at one end.
And a second end wall at the other end to define a cavity for containing the laser gas. A laser resonance path is also provided axially aligned with the gas discharge gap. A first laser optic is disposed in the laser resonance path and has a side exposed to a cavity formed by the tube. A dust removing unit is attached to the laser tube. The dust removing unit includes: (1) a high-voltage conductive core having a first end connectable to a high-voltage power supply and a second end, and an insulator element disposed around the core; A) a wire loop electrically connected to the second end of the high voltage core; The dust removal unit has the wire loop oriented transversely to the resonance path such that the wire loop is disposed inside the tube proximate the first side of the optical element and the resonance path passes through the wire loop. Attached to the laser tube.

The gas laser provided with the dust removal unit according to the present invention has the advantage that optical elements such as windows or mirrors in the tube are much less contaminated than those according to the state of the art.
Has improved properties with respect to maintenance and life.

The optical element protected by the dust removal unit can be any of the optical elements used in gas lasers. As a result, the optical element to be protected can be a totally reflective mirror, a partially transmissive and partially reflective mirror, or a completely transmissive window.

According to another object of the present invention, it is an object to provide a modular gas laser having an optical element and having improved maintainability of the optical element.

To achieve this object according to the present invention,
A modular gas laser is provided having a tube having a first end wall at one end and a second end wall at the other end. The tube defines a cavity for containing a laser gas, and the first end wall includes a port. The optical axis extends longitudinally through the tube and passes through the port. The laser further comprises a mounting structure mounted on an outer wall of the first end wall of the tube. The mounting structure includes an optical element receiving surface and an opening extending through the receiving surface.
The aperture is positioned transverse to the optical axis such that the optical axis passes through the aperture, and is aligned with the port and the optical axis. An optical element and an optical element holder are also provided.
The holder includes a tubular grip portion and a tubular extraction portion connected at one end to the tubular grip portion and having a diameter smaller than the diameter of the tubular grip portion. The tubular grip portion grasps and holds the peripheral edge of the optical element so as to secure the optical element in the optical element holder. A retainer is slidably and rotatably carried on the tubular extraction portion of the holder. The retainer also removably engages the mounting structure, securing the optical element to the optical element receiving surface and forming a gas tight seal therebetween. The optical element is arranged transversely to the optical axis such that the optical axis abuts on the optical element.

By using the optical element holder and extraction device according to this aspect of the invention in a laser, damage to the laser itself can be prevented. As a result, it is much easier to remove the optical element from the laser, thereby minimizing the potential for mechanical damage to the optical element or laser when attempting to remove the optical element from the laser tube. For example, the optics holder and extraction device may allow the holder to be loosened without completely disconnecting the holder from the mounting structure, and then rotating the holder about a common axis within the holder after the holder has been released. It is preferable to design it so that it can be performed. Further, preferably, when the holder is rotated, the optical element is also rotated.

With this embodiment, it is possible to rotate the optical element while keeping the optical element in the mounting structure without ventilating the laser system. This is particularly advantageous when the laser beam is eccentrically impinged on the optical element, since the life of the optical element can be greatly extended. In the case where the point where the laser beam collides is too dark, this embodiment can rotate the optical element occasionally, so that the life of the optical element can be extended. In other words, the optics can be rotated so that the laser beam strikes a fresh or clean portion of the optics, thereby restoring the efficiency of the laser. Further, the optics can be rotated multiple times until rotated to about 360 °, thus increasing the lifetime of the window.

Another object of the present invention is to provide a modular gas laser having an adjustable mounting unit for an optical element. In particular, it would be desirable to provide a gas laser having an adjustable optical element mounting unit that can be adjusted with improved accuracy.

To this end, the modular gas laser comprises a tube having a first end wall at one end and a second end wall at the other end. The tube defines a cavity therein for containing the laser gas, and the first end wall includes a port. The laser further includes an optical axis extending longitudinally through the tube to pass through the port. The optical axis is the axis at which laser light resonates in the laser. A rigid support structure including the aperture is mounted on the laser tube such that the optical axis passes through the aperture. The optical element is mounted in this opening. Preferably, the optical element is either a totally reflective mirror or a partially reflective and partially transmissive mirror so that the optical element constitutes one of the mirrors of the laser resonator. At least three adjustable mounting devices are used to mount the support structure to the laser tube.

To ensure that the modular laser is properly adjusted at all times, the mounting point is axially displaced by substantially the same amount of dimensional change in the laser that occurs during operation of the laser. It is preferable to select the mounting point as described above. When mounted, the rigid support structure is spaced from the end wall of the laser so that the angular position of the optical element can be adjusted. Further, the aperture and the optical element are arranged transversely to the optical axis and are aligned with the optical axis. Adjusting one of the three adjustable mounting devices changes the angular position of the optical element with respect to the optical axis.

In a preferred embodiment of this aspect of the invention, the laser further comprises a gas tight flexible tube element used to form a gas tight seal between the laser tube and the reflective optic. The flexible tube is at the base end,
Preferably, it comprises an optical element receiving end, an optical element receiving surface proximate the receiving end in the flexible tube element, and a flexible section inserted between the base end and the receiving surface. The flexure section can, for example, consist of bellows. The base end of the flexible tube is hermetically mounted to a first end wall around the port such that the optical axis of the laser passes through the flexible tube element. The outer surface of the optical element receiving end engages an open wall in the rigid support structure. Furthermore,
The optical element is received by the optical element receiving surface within the flexible tube element, and a hermetic seal is formed between the optical element and the optical element receiving surface.

As described above, by using the above-described flexible tube element, a gas tight chamber can be formed between the end wall of the laser and the optical element. This allows the laser to be designed without using a completely transparent lens on the end wall to seal the laser, thereby reducing the number of optics that must pass the laser light Can be done.

Preferably, the optical elements are symmetrically arranged between the even number of adjustable mounting devices. For example, if the even mounting point is 2, it is preferable to center the optical element on a line that bisects the center of the line connecting the two mounting points, and most preferably the two mounting points Is positioned close to the center of the line connecting. The remaining mounting points can be used to tilt the support structure and thereby adjust the optics and laser unit.

The rigid support structure may comprise, for example, a solid plate having a first arm and a second arm at an angle, or an angular structure. If an angular structure is used, the included angle is preferably 90 °. The arms, i.e. the first arm and the second arm,
It can have different lengths. However, the first arm of the rigid support structure has a length of about 2
Preferably, the opening is formed in the first arm. In a further preferred embodiment of this aspect of the invention, the mounting device is preferably arranged at the end of the arm.

The adjustable mounting devices used in connection with the present invention each include a first threaded end, a second threaded end, and a first threaded end and a second threaded end. It preferably consists of a stud with a body part inserted between them. The first threaded end is slidably received in a hole in the support structure and extends through the hole. The second threaded end is used to attach the support structure to the laser. Next, the adjusting nut is
Screwed into the threaded end of A biasing element is provided to bias the support structure away from the second threaded end of the stud and toward the adjustment nut.

Thus, with the modular gas laser of the present invention, it is possible to achieve very accurate adjustment of the laser's optical elements, even in situations where the optical elements are used to obtain a gas seal. become. Furthermore, the adjustable mounting unit is very simple and therefore inexpensive. As a result, with the adjustable mounting unit described above, it is no longer necessary to provide a complex outer support mechanism for supporting the laser optics outside the laser tube, even if precise adjustability is desired. Furthermore, gas lasers according to the present invention are more efficient because they have a short resonance distance. Still further, the gas laser according to the present invention is less expensive to manufacture than prior art gas lasers because the present invention does not require the complex support mechanisms used in typical prior art devices.

According to the present invention, there is further provided a stable support arrangement for the optics of a modular gas laser which is attached to the laser tube itself and maintains the optics in proper alignment and position regardless of the operating conditions of the laser. It is possible to provide.

The present invention is particularly suited for use in excimer lasers, since excimer lasers operate at very high pressures and temperatures. For example, excimer lasers typically operate at pressures of about 4 bar and temperatures up to 100 ° C. However, according to the present invention, it is possible to precisely adjust the laser optics in response to these required conditions. Furthermore, these adjustments do not begin to get out of order as a result of changes in operating conditions within the laser tube during laser use. Indeed, according to the invention, the optical element is supported in the device indirectly by the tube rim, so that the bending, bending and / or bending of the front part of the laser tube, for example, caused by a change in temperature or pressure in the tube.
Or, the warpage does not affect the alignment of the reflective optic mounted within the adjustable mounting structure.

The overall structure of the modular laser is such that at least an elongated electrode plate, an elongated high voltage electrode and an elongated ground electrode are pre-mounted and form a pre-adjustable modular discharge unit. Preferably, the pre-installed modular discharge unit further comprises the high voltage duct, the shadow plate, and the corona pre-ionizer. The discharge unit can be attached to a laser tube as a whole and detached from the laser tube. This offers several advantages. One advantage is that before mounting the discharge unit in the laser tube,
The ability to adjust the gas discharge gap between the high voltage electrode and the ground electrode, which facilitates accurate adjustment of the gas discharge gap. Further, the mounting of the laser can be performed more efficiently.

When the laser gas is an excimer laser, KrF, ArF, XeF, XeBr, HgBr, HgCl,
XeCl, HCl, some kind of excimer laser gases such as F _2, in the case of other gas discharge lasers may be some kind of laser gas.

In addition to the laser gas, it is preferable to supply a buffer gas made of a mixture of helium, neon, and / or argon into the tube.

[0060]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below.

The excimer laser 100 shown in FIGS. 1 and 2
Is a tube 101, a discharge unit 102, a circulation means 201,
And a laser optical system 103.

The circulating means 201 is optional and can comprise, for example, a fan or any other means for circulating the lasing gas in the gas laser.

The discharge unit 102 is mounted in the tube 101 and includes a high voltage electrode 104 and a ground electrode 105. The high voltage electrode 104 and the ground electrode 105 are spaced apart from each other, thereby defining a gas discharge gap 106. A high voltage is applied to the high voltage electrode 104 via a plurality of high voltage ducts 107 carrying the high voltage electrode 104. Each high-voltage duct 107 has a conductive core 1
08 and an insulator element 110 arranged around the conductive core 108. Each high voltage duct 107
Is mounted on the high voltage electrode using suitable fasteners. In the present embodiment, studs 112 threaded at both ends are used to attach the electrode 104 to each conductive core 108 of each duct 107.

Further, the discharge unit 102 is provided with an elongated electrode plate 111. The electrode plate 111 includes a hole through which the high voltage duct 107 connected to the high voltage electrode 104 passes. Each high-voltage duct 107 is fixed to the electrode plate 111 by a mounting means such as a bolt 113. However, if you are familiar with the field,
It will be appreciated that any suitable attachment means may be used to secure 07 to electrode plate 111.

The insulator element 110 is preferably made of a ceramic material. However, as an option, they can also be made of other insulating materials, including for example fluoride materials. These have a shape that extends conically toward the high-voltage electrode 104 and a passage extending along the surface to avoid surface flashover between the high-voltage electrode 104 and the grounded electrode plate 111. With a pleated surface that increases the

As mentioned above, the insulator element 110 can be made of a fluoride insulator material. These materials have the disadvantage of being relatively expensive. However, according to the preferred embodiment of the present invention, only a small amount of insulator material is required. Therefore, the fluoride insulator material can be used in the present invention without any problem.

As shown in FIG. 2, the discharge unit 102
Insulator element 1 due to corrosion effects of laser gas and laser radiation
Plate 210 located between gas discharge gap 106 and insulator element 110 to protect
It is preferable to further include Shadow plate 210
Is preferably made of a metal such as aluminum.
High purity metals are particularly preferred for use in constructing the shadow plate 210.

In the present embodiment, the shadow plate 210
It is inserted between the high voltage electrode 104 and the insulator element 110 of the duct 107. Preferably, the shadow plate 210
Extends along the entire gas discharge gap 106 and is mounted to at least partially shield the insulator element from laser radiation emitted from the gas discharge gap 106.

Referring to FIGS. 2 and 3a. Shadow plate 21
0 has an elongated sheet-like shape, and preferably includes a central portion 209, a first edge portion 211, and a second edge portion 212. The central portion 209 extends in a direction parallel to the gas discharge gap 106 and in a direction perpendicular to the core 108 of the high voltage duct 107. Edge portions 211 and 2
12 are located on the longitudinal edges of the shadow plate 210 and about 20
It is preferable to bend so as to form a small angle of °. Although the shadow plate 210 is preferably elongated as described above, it can have various other shapes. For example, instead of one elongated shadow plate, a plurality of shadow plates 21 extending the length of the discharge gap
0 can be used. In this case, it is preferable that the shadow plate is circular and has a cross-sectional appearance that does not contradict the one shown in FIG. Therefore, the circular shadow plate 2
10 can be inserted between the electrode 104 and each insulator element 110 of the high voltage duct 107.

As clearly shown in FIG. 2, the shadow plate 209 is positioned such that the vertical axis of the central portion 209 (or the center in the case of a circular shadow plate) coincides with the central axis of the high-voltage electrode 104. High voltage electrode 104 and high voltage duct 107
Between the core 108 and the inner end 404 of the core 108.

The shadow plate 210 is preferably inserted between the high-voltage electrode 104 and the inner end 404 of the core 108, as shown in FIG. Gap 106 and insulator element 110
It will be appreciated that the shadow plate 210 performs its desired function as long as it is inserted between them. Therefore, the position of the shadow plate 210 is not limited to the position shown in FIG.

The shadow plate 210 is provided with a plurality of holes 213 in the central portion 209 (preferably along the longitudinal axis of the central portion 209) and through these holes 213, using a suitable fastener, the high voltage electrode 104. Can be inserted between the electrode 104 and the core 108 by attaching to the core 108. Therefore, the interval and the number of the holes 213 match the interval and the number of the high-voltage duct 107. In the present embodiment, the stud 1 is threaded at both ends.
12 are used to attach the electrodes 104 to the core 108. One end of the stud 112 is inserted into a threaded hole 124 provided in each core 108. The second end of the stud 112 is inserted into another threaded hole 124 provided in the inner end 404 of the core 108 and the engaging surface 128 of the high voltage electrode 104 facing the shadow plate 210. ing. If a circular shadow plate is used, a single hole 2 in the center of each shadow plate
13, one shadow plate is used for each high voltage duct used in the laser.

The shadow plate 210 preferably has a flow guiding configuration to assist in guiding the lasing gas mixture into the gas discharge gap 106.

Hereinafter, a preferred method for assembling the electrode arrangement of the present invention having a shadow plate will be described.

First, one end of the stud bolt 112 is screwed into each threaded hole provided on the engaging surface 128 of the high-voltage electrode 104, and the other end of each stud bolt 112 projects from the engaging surface 128. Let it. Next, the shadow plate 210 is arranged on the engagement surface 128 of the high voltage electrode 104 such that the studs 112 are inserted into the holes 213 in the shadow plate 210. Alternatively, if a circular shadow plate is used, insert one shadow plate 210 over each stud 112. After disposing the shadow plate 210 at a predetermined position, the core 10 of the high-voltage duct 107
8 is lowered onto the shadow plate 210 and one end of the stud protruding from the electrode is screwed into the threaded hole 1 provided in the inner end 404 of the core 108 of the high voltage duct 107.
24 partially inserted. Next, the core 108 is rotated about its longitudinal axis, and the core 108 is inserted into the stud 1.
Screw on 12. As a result, the core 108 descends onto the shadow plate 210, and the shadow plate 210 is finally held between the upper surface 128 of the high-voltage electrode 104 and the inner end 404 of the core 108. Another high voltage duct 107 with a core 108 is attached to the remaining stud 112 in the same manner as described above.

In the case of an elongated shadow plate, the core 108
At least two cores 108 are loosely screwed into their corresponding studs 112 before the is firmly screwed into the studs 112. Next, the shadow plate 21
After the 0 is accurately positioned, all the cores 108 are sufficiently screwed down to lock the shadow plate 210 in place.

The excimer laser 100 is preferably
Pulsed argon fluoride (Ar) having a wavelength of 193 nm
F) Excimer laser. This means using argon fluoride gas to generate the laser beam. However, those skilled in the art will appreciate that any known excimer laser gas can be used with the present invention.

By applying a high-voltage pulse of about 20 kV to the high-voltage electrode 104, the laser gas (eg, argon fluoride gas) in the discharge gap 106 and, additionally, helium and / or argon gas as a buffer gas are supplied. A laser beam is generated, and the beam is
And emitted through the rear optics 120.

The laser 100 typically includes a front optic 116 through which a laser beam is emitted. The optical element 116 can be provided in an optical system 103 that includes, for example, adjustable mounting means 117 for adjusting the position of the optical element 116 with respect to the tube 101. The rear laser optics 120 also includes an optical element 116 (not shown) and adjustment means 117. However, the optical element 116 of the rear laser optical system 120 is not a partial reflection mirror but a total reflection mirror. As will be appreciated by those skilled in the art, the front and rear optics 116 may be mounted directly within the end wall of the laser tube 101. Alternatively, they can be mounted on an adjustable mounting bracket that is separate from the laser tube 101, as is known in the art. Preferably, the structure of the adjustable mounting unit comprises a tube 1
It is similar to the adjustable mounting unit used for the end wall 96 of FIG. However, laser 1
00 can also be designed such that the rear optic 116 is mounted in full alignment with the resonance path in the laser tube 101. For example, the rear optic 116 may be mounted on the inner wall of the rear end wall 98 of the tube 101 or, alternatively, the outer wall of the rear end wall to cover a port 97 formed in the rear end wall. Can be mounted on top. If the optical element 116 is provided on the outer wall of the rear end wall 98, the optical element can be mounted using a flange structure as is known in the art. 9, 10 and 11, the front and rear optics 10
Reference will be made to laser optics and adjustable mounting means suitable for use with the present invention as 3,120.

The adjustable mounting unit 103 has a rigid support structure 117 having an opening defined by an opening wall 122. The optical element 116 is mounted in the opening. First, second, and third adjustable mounting devices 700 are provided for mounting the support structure to the laser at three separate points. Preferably, the mounting point is selected such that the mounting point is axially displaced by substantially the same amount as the dimensional change that occurs in the laser as a result of temperature and pressure changes during operation of the laser. Therefore, to minimize deviations in the angular alignment of the optics during operation of the laser, it is preferred that the mounting point be located close to the perimeter 706 of the tube, as shown in FIG. By selecting the point of attachment as close as possible to the edge 706 of the tube 101, any bending, bending, and / or warping of the end wall 96 due to changes in temperature or pressure within the tube 101 can be achieved. The alignment of the reflective optics mounted on the adjustable mounting unit will not be affected.

When the adjustable mounting unit 103 is mounted on a laser tube, the rigid support structure 117 is spaced from the laser end wall 96 so that the angular positioning of the optical element 116 can be adjusted. Further, the aperture and the optic are positioned across the optical axis and are aligned with the optical axis. As a result, adjusting the adjustable mounting device 700 changes the angular position of the optical element with respect to the optical axis.

As shown in FIG. 9, a rigid support structure 117 is provided.
Consists of an L-shaped structure including a first arm 701 and a second arm 702, which are preferably joined together at one end 704 thereof. It is preferable that the first arm 701 be longer than the second arm 702. Preferably, the first arm 701 is about twice as long as the second arm 702 and has a hole in the center of the first arm 701. The first arm 701 and the second arm 702 form an angle 703 between them.
In the present embodiment, the angle 703 is set to 90 ° so that the optical element can be adjusted most easily and most accurately. However, various angles can be used, as will be appreciated by those skilled in the art.
Also, as will be appreciated by those skilled in the art, the rigid support structure 117 may take various other forms. For example, the rigid support structure 117 can be a T-shaped or triangular solid plate structure with an adjustable mounting device 700 at each apex of the triangle.
Similarly, the rigid support structure 117 may consist of a square or circular plate.

Although the illustrated embodiment uses three adjustable mounting devices 700, as will be appreciated by those skilled in the art, other embodiments of the present invention may have additional An adjustable mounting device 700 can be used.

The use of the L-shaped rigid support structure 117 as shown in FIG. 9 greatly facilitates the symmetric adjustment of the optical element 116. This is in part because the arms of the rigid support structure 117 essentially form an eccentric lever with respect to the front end wall 96 of the optical element and tube. In addition, the first arm 701 and the second
Arms 702 are integrally attached to one another at their one end portions 704. As a result, the arms 701 and 702 have a rigid support structure 117.
Share a common adjustable mounting device 700 for mounting the to the laser tube.

When the optical element 116 is adjusted using one of the two non-shared adjustable mounting devices 700, the arms 701, 702 are coordinated with the origin at the center of the shared adjustable mounting device 700. If so, the optical element 116 essentially rotates about the x or y axis. In other words, x
The axis is parallel to the first arm 701, and the y axis is
Is an axis parallel to.

As described above, the adjustable mounting units 103 and 120 according to the present invention are highly symmetrical for adjusting the reflective optical element 116 constituting the laser resonator with respect to the optical axis, and It offers an easy way.

Adjustable mounting device 7 according to the invention
00 preferably includes a stud bolt 803, a biasing element 802 such as a coil spring, and an adjustment nut 705.
It is preferable to include As shown in FIG. 11, each stud 803 preferably comprises threaded ends and a body portion inserted between the threaded ends.
Preferably, as shown, the diameter of the body portion is greater than the threaded ends. A first threaded end 804 of the stud 803 is slidably received through a hole in the rigid support structure 117 such that the first threaded end extends through the support structure. The second threaded end is used to mount the support structure 117 to the end wall 96 of the laser tube 101 (or to the end wall 98 in the case of the adjustable mounting unit 120). A coil spring 802 is slidably carried on the body portion of the stud 803 and extends through a rigid support structure.
Screw the adjustment nut 705 into the first threaded end of the.
As a result, the support structure 117 is slidably inserted between the adjusting nut 705 and the first end of the coil spring. When the threaded end of the stud is attached to the laser tube, the spring 8
02 moves the support structure 117 away from the second threaded end of the stud 803 toward the adjustment nut 705.

Preferably, the stud 803 further comprises a spring stop 808 located on the body portion that abuts the second threaded end of the stud. The second end of the coil spring 802 has a spring stop 8
08 and a spring stop 808 to be inserted between the rigid support structure 117.

As shown in FIG. 11, a recess 820 is preferably provided in the rigid support structure 117 to receive the first end of each coil spring 802 of the adjustable mounting device 700. In this embodiment, the concave portion 820 is provided at each end portion 7 of the first arm 701 and the second arm 702.
04. Accordingly, each recess 820 is provided with a coil spring 8 carried on a corresponding stud 803.
02 one.

The adjustment nut 705, spring 802, and stud 803 mount the rigid support structure 117 on the perimeter 706 of the end wall 96 of the laser tube 101, as shown in FIG. Can be used for mounting on.

Preferably, the adjustable mounting unit 103, 120 according to the invention is adapted for mounting the end wall 9
It further comprises a gas tight flexible tube element 800 that can be used to form a gas tight seal between the 6, 98 and the reflective optical element 116. Preferably, the flexible tube element has a base end 806, an optical element receiving end 80,
9, including an optical element receiving surface 807 in the flexible tube element proximate the receiving end, and a flexible section 805 inserted between the base end 806 and the receiving surface 807. The flexure section 805 can consist of bellows, for example.

The flexible tube base end 806 is hermetically mounted to an end wall 96 around a port 97 so that the optical axis of the laser passes through the flexible tube element. If the end wall 98 is also provided with an adjustable mounting unit, the base 806 of the second flexible tube element is hermetically mounted to the end wall 98. The base end 806 is preferably hermetically mounted to a suitable end wall by welding or brazing. The outer surface of the optical element receiving end 809 engages the opening wall 122 of the rigid support structure 117. Further, the optical element 116 is received by an optical element receiving surface 807 in the flexible tube element;
A seal 812, such as an O-ring, is provided between the optical element 116 and the optical element receiving surface 807 to assist in forming an airtight seal therebetween.

The outer surface of the optical element receiving end 809 is connected to the opening wall 1.
22 so that the inner screw 81
7 with the flexible tube element 8
00 can be screwed onto corresponding external threads provided on the outer surface of the optical element receiving end 809. Locking ring 811 is threaded on receiving end 809 until it abuts rigid support structure 117. Further rotation of the locking ring 811 in the tightening direction after the locking ring 811 abuts the rigid support structure 117 causes the flexible tube element 800 to be drawn into the opening and come into contact with the opening wall 122. By making the opening wall 122 narrower towards the side farther from the laser, ie by tapering the opening wall 122 as such,
The frictional engagement between the optical element receiving end and the opening wall can be further improved.

Adjustable mounting units 103, 120
Preferably further includes an optical element holder 710. Holder 710 holds or secures optical element 116 to optical element receiving surface 807 and seal 812, thereby providing optical element and optical element receiving surface 8.
07 to help maintain a gas tight seal. The retainer 710 engages the optical element receiving end 809 of the flexible tube element 800 to ensure that the optical element 116 is held in place when the laser gas contained within the laser tube is pressurized. In the present embodiment, the holder 71
O comprises an externally threaded sleeve that is screwed into the inner surface of the optical element receiving end 809. As a result, the optical element 116
Is inserted between the retainer 710 and the optical element receiving surface 807, thereby improving and maintaining the seal formed between the optical element and the receiving surface.

As described above, the above-described flexible tube element 80
The use of 0 allows the optical element 116 to be used to seal the laser tube 101 and to adjust the optical element angularly. Thereby,
The laser can be designed without the use of completely transparent lenses mounted directly on the end walls 96, 98 to seal the laser, reducing the number of optical elements that must pass the laser light. be able to.

[0096] Preferably, the optical elements 116 are symmetrically disposed between the even number of adjustable mounting devices 700. For example, if the selected even fixed point is 2, the center of the optical element 116 is preferably on a line that bisects the line connecting the two fixed points at their center point, more preferably As shown in FIG. 9, the positioning is performed so as to be in close contact with the center of the line connecting the two fixed points. The remaining fixing points can be used to tilt the support structure and thereby adjust the optics and laser unit.

A seal 814, such as an O-ring, may also be provided between the annular shoulder 815 of the retainer sleeve 710 and the optic receiving end 809 of the flexible tube element. The laser beam delivery area between the optical element 116 and the work piece must be evacuated or alternatively filled with a gas such as nitrogen to allow proper transmission of the laser beam to the work piece. In situations where this must be done, the use of a seal 814 is advantageous.

According to the present invention, holder 710 forms part of optical element holding and extracting device 408.
Optical element retention and extraction device 408 is used to help minimize the possibility of damaging optical element 116 during maintenance and installation. The optical element holding and extracting device 408 includes a holder 710 and an optical element holder 82.
2 is provided. The optical element holder 822 includes a grip portion 818 for gripping the optical element and a tubular extraction portion 819 attached to the grip portion.

As shown in FIGS. 10 and 11, the gripping portions 818 are arranged to grip around the periphery of the optical element 116. To achieve this gripping arrangement, the gripping portion preferably comprises an annular clip and a stop 813 for receiving the optical element. A stop 813 is provided on the inside diameter of the annular clip and abuts against the laser side of the optical element 816 to assist in locking the optical element within the annular clip of the grip portion 818. Stop 813 may consist of, for example, a snap ring or other locking mechanism such as a detent. As mentioned above, stop 8
13, with the aid of an optical element holding and extracting device 40
When the 8 is removed from the adjustable mounting structure 103 or 120, the optical element 116 is prevented from falling off the grip portion 818. This is true even though the O-ring seal 812 tends to stick to the engagement surface with the optical element 116, and thus tends to pull the optical element toward the laser tube 101.

A further advantage of the optical element holding and extracting device 408 according to the present invention is that the grip portion 818 includes a shoulder inserted between the optical element 116 and the retainer sleeve 710. As a result, when the holder sleeve 710 is screwed into the optical element receiving end 809 of the tube element 800, the optical element is not scratched because the holder sleeve does not directly contact the optical element.

[0101] The tubular extraction portion 819 includes a grip portion 818.
Is connected to one end. The axis of the tubular extraction portion 819 extends longitudinally in a direction parallel to the optical axis of the laser.
The tubular extraction section is constructed such that the outer wall of the extraction section is
Preferably, it has a size that slidably abuts the inner wall of the zero. As a result, the tubular extraction portion slidably engages the inner wall of the retainer sleeve 710. Further, the tubular extraction portion 819 is preferably longer than the corresponding length of the portion of the retainer 710 that slidably engages the tubular extraction portion.

It is preferable to provide a catch 816 on the outer surface of the tubular extraction portion of the optical element holder 822. The catch 816 can be, for example, a snap ring or a detent. The catch 816 includes the tubular extraction portion 8
Preferably, it is provided close to the end opposite to the end connected to the grip portion 818 of the nineteen.

When the holder 710 is removed from the optical element receiving end 809, the holder 710 can be slid along the surface of the tubular extraction portion 819 of the optical element holder 822 until the holder 710 contacts the catch 816.
When the retainer 710 is subsequently pulled away from the laser, a force is applied via the catch 816 to the tubular extraction portion 81.
9 and from the grip portion 818 to the optical element 816. As a result, the optical element can be easily and safely removed from the optical receiving surface 807, while greatly reducing the risk of potentially damaging the optical element 816.

Another advantage of using the optical element holding and extraction device 408 with a modular gas laser in accordance with the present invention is that the optical element 116 can be secured in any desired rotational position within the optical element receiving surface 807. is there. In other words, the optical element 116 can be rotated at any angle about a rotation axis that extends parallel to the emitted laser beam, and thus the optical axis. Further, the optical element and extraction device 40 according to the invention
With 8, a rotation can be achieved without first emptying the laser gas.

In order to rotate the optical element 116, the holder 710 is loosened. However, loosening of this retainer 710 is only sufficient to allow rotation of the optics retention and extraction device 408 while keeping the optics 116 gas tightly sealed to the receiving surface 807. . After the retainer 710 has been sufficiently loosened, the optics retention and extraction device 408 can be rotated by grasping the tubular extraction portion 819 and rotating it in the desired direction. If necessary, a pair of pliers can be used to assist in rotating the device 408. As described above, simply rotating the holder 822 does not damage the optical element 116 or eliminates the need to empty and then refill the laser gas in the laser.
The optical element 116 can be rotated while continuing to seal the receiving surface 807 in a gas-tight manner. Therefore, rotation of the laser optical element 116 can be achieved in a very simple manner.

The ability to rotate the optical element without first emptying the laser gas is desirable from a laser maintenance standpoint. As described above, the laser light tends to darken the central portion of the optical element 116. Thus, by allowing the optical element to rotate periodically, the undarkened portion of the optical element can be rotated to the point where the laser beam strikes the optical element, thereby reducing the efficiency of the laser. Some can be recovered. Of course, this assumes that the laser beam strikes the optical element at a point eccentric to the axis of rotation of the optical element. However, if one is familiar with the art, it would be easy to design the laser such that the laser beam strikes the optics slightly off-center.

From the above description, it can be easily understood that according to the present invention, the holder is preferably a sleeve with an external thread, and the optical element is preferably circular. Preferably, the optical element holder is also formed to be rotationally symmetric. Finally, the optical element holder,
Preferably, the holder and the optical element share a common axis of rotation.

After rotating the optical element by the desired angle, the retainer 710 is tightened to maintain a gas tight seal between the optical element 116 and the receiving surface 807.

As will be appreciated by those skilled in the art, an optical element holding and extracting device 408 according to the present invention.
Is not limited to use with the adjustable mounting unit 103 or 120 as described in the preferred embodiment. In fact, the optical element holding and extracting device of the present invention can be used with optical elements mounted in non-adjustable mounting structures. For example, optical element retention and extraction device 408
Can be used with optical elements mounted directly on the end wall of the laser tube. In this situation, the mounting structure formed by the optical element receiving end 809 and the receiving surface 807 of the flexible tube element can be machined directly into the end wall of the laser, for example. Alternatively, the mounting structure provided by optical element receiving end 809 and receiving surface 807 can be formed by one or more flanges mounted on the end wall of the laser tube. The mounting structure formed by the optical element receiving end 809 and the receiving surface 807 can also be provided in an optical arrangement separate from the laser tube.

FIG. 2 shows an excimer laser 100 shown in FIG.
FIG. 2 is a sectional view taken along line 2-2 of FIG. As shown in FIG. 2, the excimer laser 100 includes a circulating means 112 such as a fan for circulating the excimer laser gas through the discharge gap 106 and an optional dust removing unit 202 for dusting the gas flow through the tube 101. It is preferable to further include In operation, a gas discharge occurs in the gas discharge gap between the electrodes 104 and 105, thereby generating a laser beam. The gas flow generated by the radial fan 201 passes between the electrodes 104 and 105, thereby providing a continuous supply of fresh lasing gas to the gas discharge gap 106.

Referring to FIG. The discharge unit 102 and the dust removal unit 202 preferably extend along the opposite side of the inner wall 140 of the tube 101. The inner wall 140
Preferably, the tube 101 is cylindrical so that its cross section is circular over the entire length. Radial fan 20
1 is attached along a part of a cylindrical inner wall 140 extending between the discharge unit 102 and the dust removal unit 202. To assist in reducing the size of the laser unit 100, the discharge unit may include a radial fan 201.
It is preferred that the dimensions be such as to accommodate the section of the radial fan 201 such that the exhaust side of the fan can be located close to the gas discharge gap 106. For example, in the present embodiment, the flow guide 209 is provided with a concave arch-shaped section 220 so that the exhaust side of the radial fan 201 can be arranged close to the discharge gap 106.

It is also preferable that the laser unit 100 be provided with two curved and elongated guide plates 205. The curved guide plate 205 is symmetrically attached to the inner wall 140 of the tube 101 on both sides. The guide plate 205 is elongated in the longitudinal direction of the tube 101. Further, as shown in FIG.
5 is curved to guide the gas exiting the exhaust side of the fan 201 through the gas discharge gap 106 and to return the gas to the inlet side of the fan 201 for recirculation.

The dust removing unit 202 has a cylindrical inner wall 140.
A substantially circular central section 232 extending substantially parallel to
And an elongated partition wall 230 having End 23 of partition wall 230 extending to the exhaust side of dust removal unit 202
4 is bent towards the cylindrical inner wall 140 of the tube 101. Mounted on the convex side 238 of the central section 232 of the partition wall 230 are a plurality of elongated U-shaped channels 204 spaced apart parallel to one another. As a result, the legs 236 of the U-shaped channel 204 are
4, extending in a direction parallel to 105. As best shown in FIG. 5a, the legs 236 of the U-shaped channel 204
Consists of perforated walls. Connect the high voltage wire 203 to each U
It preferably extends between the two perforated walls 236 of the U-shaped channel 204 and between the perforated walls 236 of the adjacent U-shaped channel 204.

During the operation of the gas laser according to the preferred embodiment of the present invention, the radial fan 201
Generate a gas discharge that passes through a gas discharge gap 106 that ionizes the laser gas between the high-voltage electrode 104 and the ground electrode 105 to generate a gas discharge and generate laser light. The gas flow then proceeds from the gas discharge gap 106 along the second guide plate 205 and along the inner cylindrical wall of the tube 101,
To the dust removal unit 202 arranged on the opposite side of the discharge unit 102 of the second embodiment. The bypass flow, which is a part of the gas flow in the pipe 101, is formed between the partition wall 230 and the cylindrical inner wall 1.
40 through the inlet portion 240 of the dust removal unit 202 defined between the two. The end 242 of the partition wall 230 extending toward the inlet side of the dust removing unit 202 is slightly inclined toward the cylindrical inner wall 140 of the pipe 101. The bypass flow strikes and passes through the perforated wall 236 of the elongated U-shaped channel 204. As a result, the dust particles contained in the bypass flow are electrostatically charged by the high voltage wire 203, thereby causing the dust particles to move into the cylindrical inner wall 140.
Deflected toward Bending the exhaust end 234 of the partition wall 230 toward the cylindrical wall 140 is advantageous because it also directs the flow of charged dust particles toward the cylindrical wall 140 and helps them to adhere. is there.

The cleaned bypass flow is supplied to the partition wall 230.
At the bent end 234 of the compartment wall 230
Rejoins the main gas stream guided along the side facing away from the cylindrical inner wall 140 of the main gas. The main gas flow and the bypass gas flow rejoin at the outlet side of the dust remover 202,
The combined flow is supplied to the radial fan 201.

By passing only a part of the gas flow in the tube 101 through the dust removing unit 202, the laser tube 10
1 and, in particular, in the gas discharge gap 106 are not disturbed. as a result,
During laser operation, little or no turbulent gas circulation within the tube 101 is obtained. Therefore, the two electrodes 104
A continuous gas flow is supplied to the gas discharge gap between and 105 to achieve effective ionization of the gas mixture.

In operation, since the gas flow is continuous, only a small bypass flow passes through the dust removal unit,
It has been found that it is sufficient to sufficiently remove all gas contents in the pipe.

The ground electrode 105 is preferably carried by or attached to the electrode plate 111 via a plurality of flow guides 209 described below.

[0119] Two pre-onizers 206 are provided in contact with the high voltage electrode 104, and pre-ionize the laser gas to further homogenize the gas discharge in the discharge gap 106.

The pre-onizer 206 is preferably a corona-type pre-onizer, and extends substantially parallel to the high-voltage electrode. The play-onizer 206 has a coaxial shape, and the conductive core 207 is surrounded by a tubular insulator 208.

The corona-type pre-ionizer can be mounted immediately near the high-voltage electrode. Specifically, as shown in FIG. 2, the corona-type pre-onizer is arranged close to the electrode surface of the high-voltage electrode facing the ground electrode.
Should be attached to both edges of the high voltage electrode.

Although a corona-type play-onizer is preferred as the play-onizer 206 in connection with the present invention, as will be appreciated by those skilled in the art, any play-onizer known in the art may be used. Can also. Further, the insulator of the preionizer can be Teflon or any suitable insulator, but is preferably a ceramic material. Also,
It can also be a fluoride material. Alternatively,
Other types of known play-onizers can be used. A play onizer is not necessary for operating the discharge unit. In fact, excimer lasers were known before the invention of the play-onizer. However, preionization makes the gas discharge between the high voltage electrode and the ground electrode more homogeneous and therefore more reliable.

Referring to FIGS. 3a and 3c. The discharge unit 102 has three coaxial waveguide high voltage ducts 107 extending through holes in the electrode plate 111. Duct 1
07 are arranged apart from each other. The hole and the duct 107 have a circular cross section as shown in FIG. 3c. Each of the three ducts 107 is inserted into each of the holes in the electrode plate 111 with limited tolerance between the insulator element and the hole. As will be appreciated by those skilled in the art, the number of ducts used for a particular gas laser will depend on the overall length of the laser.

[0124] The ground electrode 105 is preferably carried by or attached to the electrode plate 111.
As shown in FIGS. 2 and 3a, it is preferred to use a plurality of flow guides 209 for this purpose.

The flow guide 209 is preferably made of a sheet of metal and has electrodes 104, 10 between the electrode plate and the ground electrode.
5 extend in a plane perpendicular to the vertical axis. Flow guide plate 209
Are upper flange 301 and lower flange 30 respectively.
3 and the upper flange 301 is replaced with a lower flange 303
And a central flow guide portion 302 integrally connected to The upper and lower flanges 301, 303 extend at right angles to each other and to the central flow guide portion 302. The upper flange 301 is provided on the side surface 304 of the electrode plate 111.
, And the lower flange 303 is attached to the bottom surface 305 of the ground electrode 105. Central flow guide section 30
The 2 is preferably aerodynamically profiled to minimize flow resistance and turbulence so as to maintain substantially laminar gas flow between the flow guides.

The lower flange 303 has an oval hole 306.
(Shown only in part of the flow guide plate 209). The hole 306 is elongated in a direction perpendicular to the longitudinal axis of the elongated ground electrode 105. A screw or other fastening means 307 is screwed through the hole 306 into a corresponding screw hole 308 provided in the ground electrode 105. Oval hole 306
This allows the ground electrode 105 to be adjusted essentially against the high voltage electrode 104 in the direction indicated by the double-headed arrow 320 in FIG. 3c.

The upper flange 301 has an oblong hole 309.
It is preferable to include The hole 309 is elongated in a direction perpendicular to the longitudinal axis of the electrode plate 111. A screw or other fastening means 310 is screwed through the hole 309 into a corresponding screw hole 311 provided in the high voltage electrode 104. The oval hole 309 allows the high voltage electrode 104 to be connected to the ground electrode 10.
5 can be adjusted essentially in the direction indicated by the double-headed arrow 322 in FIG. 3a.

FIG. 4 is a sectional view of the discharge unit 102 according to the preferred embodiment of the present invention. That is, FIG.
FIG. 3 is an enlarged cross-sectional view of the discharge unit shown in FIG. The viewing angle in this figure is the same as in FIG. 3b.

Each high voltage duct 107 of the laser discharge unit 102 preferably further includes a sleeve 401 enclosing the core 108 and the insulator 110. Sleeve 4
01 is the inner end 40 supported by the electrode plate 111
2 and an outer free end 403. Core 108
Has an inner end 404 connected to the high voltage electrode 104 and a threaded outer free end 405 extending beyond the free end 403 of the sleeve 401. As shown in FIGS. 3 c and 4, a nut 406 can be screwed onto the threaded end 405, which pulls the sleeve 401 against the electrode plate 111 and tensions the core 108. Preferably, a washer 4 is provided between the nut 406 and the insulator 110 to evenly distribute the stress applied to the insulator 110 by the nut 406.
Insert 50. To connect the inner end 404 of the core 108 and the high voltage electrode 104, the threaded stud 112
Is used.

[0130] At the inner end 404 of the core 108, a coring shoulder 408 is provided so that the core 108 is pressed against the ceramic insulator element 110 when pulled up. Preferably, a seal 409 is provided between the ring shoulder 408 and the ceramic insulator element 110.

When the core 108 is pulled, the ceramic insulator element 110 is also pressed against the electrode plate 111 via the coring shoulder 408 at the inner end 404 of the core 108. Preferably, a ring shoulder 410 is provided on the insulator element 110,
Another seal 411 is provided between the ceramic insulator ring shoulder 410 and the electrode plate 111.

Preferably, a sealing ring 412 (see also FIGS. 2 and 3c) surrounds each sleeve to provide additional sealing. The sealing ring 412 can be made to have a flange 413 on its outer periphery. The flange 413 is connected to the duct 107.
Outer rim 414 of the hole 150 of the tube 101 into which is inserted
Dimensions as supported by The electrode plate 111 has a ring shoulder 41 facing the inner rim 415 of the tube 101.
7 is preferably provided. Attach metal seal 416 to shoulder 4
Preferably, it is inserted between 17 and the rim 415. As a result, when the ring 412 and the electrode plate 111 are connected by the screw 113, a gas tight seal is obtained between the shoulder 417 and the inner rim 415 of the tube 101.

All seals 409, 411, and 416
Is a ring-shaped metal seal in the present embodiment. However, as will be appreciated by those skilled in the art, the present invention is not limited to the use of ring-shaped seals.

FIG. 6 is a partially cutaway side view of another embodiment of the modular gas laser in which the dust removing unit for a laser optical element according to the present invention is used.
As shown in FIG. 6, the laser 100 includes a dust removal unit 11 for an optical element 116 in a front end wall 96 and a rear end wall 98.
5 is preferably provided. Although it is preferred to use a dust removal unit 115 for each optical element 116, the present invention also contemplates using only one dust removal unit 115 for optical element 116 for one. If only one dedusting unit 115 is used, it is preferably used for an optical element 116 that is designed to emit laser light from a laser. In the embodiment shown in FIGS. 1 and 3, this corresponds to the optical element 116 mounted on the front end wall 96.

As is clear from FIG. 7, the dust removing unit 1
15 is arranged in front of the window 116 of the tube 101. This is true whether the optical element 116 is mounted in the adjustable mounting means 103, 120 as shown in FIG. 1 or directly in the end walls 96, 98 as shown in FIG. Regardless, it has been so.

Referring to FIG. 7 and FIG. Dust removal unit 11
5 includes a high-voltage duct 501 and a wire loop 502. The high voltage duct 501 comprises a high voltage conductive core 504 and an insulator element 503 disposed around the core.
It has. One end of the high voltage core is connectable to a high voltage power supply (not shown) and the second end is electrically connected to the wire loop 503. Preferably, insulator element 503 is made of a ceramic material.

The high voltage duct 501 is preferably formed as a waveguide tubular coaxial duct consisting of a cylindrical ceramic tube 503 and a high voltage wire 504 projecting coaxially into the insulating tube 503.

The dust removal unit 115 preferably flattens the wire loop 502 into an elongated loop such that the width of the wire loop is smaller than the diameter of the hole 605 of the tube end wall 96, preferably the outer diameter of the high voltage duct 501. By installing the laser unit in the laser unit 100. Then, first the elongated wire loop reaches the inside of the tube,
The dust removing unit 115 is inserted by passing the wire loop end through the hole 605 until at least a part of the high voltage duct 501 reaches the inside of the hole 605. Next, the wire loop is expanded to a desired shape. This shape traverses the laser resonator and is positioned so that it is close to the inwardly facing surface of optical element 116 and that the resonator passes through the wire loop. Preferably,
The diameter of the widened loop is sufficient to allow the resonant laser light in the tube to pass through the wire loop 502 without interference.

As will be appreciated by those skilled in the art, if the wire loop is elongated from the beginning,
If the diameter is smaller than 5, the step of flattening can be omitted. However, in this case, the wire loop should be large enough to be able to expand to a diameter larger than the diameter of the hole, so that when unfolded, the resonant laser light can pass through the wire loop 502 without interference. is there.

Preferably, holes 605 extend radially through the end wall where the optical element 116 to be protected is mounted. However, it is also possible to construct a high voltage duct 501 in which the dust removal unit can be inserted through a hole extending laterally through the end wall where the optical element 116 to be protected is mounted.

After the dust removal unit 115 is installed, a circular wire loop end portion 502 is placed in front of and close to the inside facing surface of the end wall 96 on which the optical element 116 is mounted. Wire loop end 50
2 is electrically coupled to a high voltage power supply (not shown) via a high voltage conductor 504 forming the conductive core of the waveguide coaxial duct 501. The high voltage power supply can be provided inside or outside the laser tube 101.

As shown in FIG. 8, the dust removing unit 115 includes fixing means 602, 603, 604 for connecting the dust removing unit 115 to a high voltage source (not shown) inside or outside the tube 101. 608. The fixing means includes, for example, a flange for fixing to the housing of the high-voltage power supply.

When a high voltage is applied to the wire loop 502, an electric field having a very high field gradient is generated. As a result of this electric field, the dust particles in the tube 101 are electrostatically charged,
Thereby they are displaced and the window 116 cannot be easily reached. Dust particles are displaced from the walls of the small chamber 607, which can be provided in the port 97 or alternatively in the inner wall of the tube.

That is, the difference between the latest devices and the device according to the invention is that the optical element itself is not used to push away the electrostatically precharged dust particles. Instead, pre-electrostatically uncharged dust particles are charged by the high field gradient electric field created by the wire loop 502, displacing the charged particles.

From the above description, the dust removal unit 115 is
Naturally, the rear optical element 1 mounted on the rear end wall 98
It should be understood that a different optical element such as 16 can also be mounted. Further, the dust removal unit 115 of the present invention may be a mirror (total reflective or partially reflective and partially transmissive mirror) or any other optical element (eg, a reflective laser optic is a tube). Can be used to protect a variety of optical elements, including 100% transmissive windows). The dust removal unit of the present invention can be completely housed in the laser tube (so both sides are exposed to the laser cavity and the dust therein)
It can also be used to protect optical elements.

As will be appreciated by those skilled in the art, the present invention may be embodied in other specific forms without departing from the spirit and scope of the invention. It should be understood that the above description of the embodiments is merely an example and does not limit the present invention described in the claims.

[Brief description of the drawings]

FIG. 1 is a side view showing a part of an excimer laser according to a preferred embodiment of the present invention, with a portion cut away.

FIG. 2 is a cross-sectional view of the excimer laser shown in FIG.

FIG. 3a is a side view of a discharge unit according to a preferred embodiment of the present invention.

FIG. 3b is a front view of the discharge unit of FIG. 3a.

FIG. 3c is a plan view of the discharge unit of FIG. 3a.

FIG. 4 is a detailed sectional view of a discharge unit according to a preferred embodiment of the present invention.

5a is a side view of the U-shaped channel of the discharge unit shown in FIG. 2;

5b is an end view of the U-shaped channel of the discharge unit shown in FIG. 2;

FIG. 6 is a partially cutaway side view of another embodiment of a modular gas laser in which a dust removing unit for a laser optical element according to the present invention is used.

FIG. 7 is a front view of a dust removing unit for the laser optics by the laser of FIG. 6, wherein the dust removing unit is inserted between the gas discharge gap and the optical element mounted on the end wall of the laser tube; FIG.

FIG. 8 is a sectional view of the dust removing unit shown in FIG.

FIG. 9 is an end view of the laser shown in FIG. 1, showing an adjustable mounting unit for the optics of the laser, particularly including the optics holding and extracting device according to another embodiment of the invention; is there.

FIG. 10 is a sectional view of the adjustable mounting unit and the end wall shown in FIG.

FIG. 11 is an enlarged cross-sectional view of a portion of the adjustable mounting unit shown in FIG. 10, clearly showing an optical holding and extracting device according to this embodiment of the present invention.

[Explanation of symbols]

 96, 98 Laser tube end wall 97 Port 100 Excimer laser 101 Tube 102 Discharge unit 103 Laser optical system 104 High voltage electrode 105 Ground electrode 106 Gas discharge gap 107 High voltage duct 108 Conductive core 110 Insulator element 111 Electrode plate 112 Stud bolt 113 Bolt 115 Dust removal unit 116 Front optical element 117 Shame optical element of support structure 120 Opening wall 124 Threaded hole 128 Engagement surface 140 Inner wall of tube 150 Duct insertion hole of tube 201 Circulation means (radial fan) 202 Dust removal unit 203 High voltage wire 204 U-shaped channel 205 guide plate 206 play onizer 207 conductive core 208 annular insulator 209 flow guide plate 210 shadow plate 211 first edge portion of shadow plate 212 shadow plate Second edge portion 213 Hole 220 Concave arched section 230 Partition wall 232 Central section of partition wall 234 Exhaust end of partition wall 236 Leg of U-shaped channel 238 Convex side of central section of partition wall 240 Inlet portion of dust removal unit 242 section Wall entry end 401 Sleeve 402 Inner end of sleeve 403 Outer end of sleeve 404 Inner end of core 405 Outer end of core 406 Nut 408 Optical element retention and extraction device 409, 411 Seal 410 Insulator ring shoulder 412 Sealing ring 413 Sealing ring Flange 414 Outer rim of tube hole 415 Inner rim of tube hole 416 Metal seal 417 Electrode plate ring shoulder 450 Washer 501 High voltage duct 502 Wire loop 503 Ceramic tube 504 High voltage wire 605 Hole in tube end wall 607 Cha Bar 700 Mounting device 701 First arm 702 Second arm 703 Angle formed by arm 704 End portion of arm 705 Adjustment nut 706 Perimeter of tube 710 Optical element holder 800 Gas tight flexible tube element 802 Bias element 803 Stud bolt 804 One end of bolt 805 Deflection section 806 Base end 807 Optical element receiving surface 808 Spring stop 809 Optical element receiving end 811 Locking ring 812, 814 Seal 813 Stop 815 Holder shoulder 816 Catch 817 Internal screw 818 Handle part 819 Extraction part 820 recess 822 optical element holder

 ────────────────────────────────────────────────── ─── Continued on the front page (31) Priority claim number 09/510666 (32) Priority date February 22, 2000 (2000.2.22) (33) Priority claim country United States (US) (31) Priority claim number 09/510667 (32) Priority date February 22, 2000 (2000.2.22) (33) Priority claim country United States (US) (31) Priority claim number 09/511648 (32) Priority date February 22, 2000 (Feb. 22, 2000) (33) Priority claim country United States (US) (31) Priority claim number 09/511649 (32) Priority date February 22, 2000 ( (22.2.2) (33) Priority Countries United States (US) (72) Inventor Alexander Hora Germany 80798 Munich Neureuter Straße 32 (72) Inventor Helmut Flovine Germany 81243 Yunhen beer Baum Sutra over cell 1 Ah

Claims (38)

[Claims] 1. A modular gas laser, comprising: a tube accommodating a gas mixture constituting a laser gas; and a discharge unit removably mounted inside the tube. An elongated electrode plate, an elongated high voltage electrode, and an elongated ground electrode, wherein both the high voltage electrode and the ground electrode are in a spaced apart relationship with their longitudinal axes substantially parallel. The discharge unit is a modular discharge unit that is mounted on the electrode plate so as to limit a gas discharge gap between the electrodes, and that can be detachably mounted in the tube as one integrated unit. Yes, the discharge electrode is
When the discharge unit is completely removed from the tube,
A modular gas laser, adjustable with respect to the other. 2. The discharge unit further includes a plurality of high voltage coaxial ducts, each duct extending through a hole in the electrode plate, each duct comprising a central conductive core and the core. An insulator element electrically insulating from the electrode plate, wherein the high-voltage electrode is electrically connected to the core of the duct, and the ground electrode is electrically connected to the electrode plate. The modular gas laser according to claim 1, wherein: 3. The duct is inserted into a respective hole in the electrode plate, and there is a limited distance between the insulator element and a respective hole in the electrode plate into which the respective duct is inserted. The modular gas laser according to claim 2, wherein the gas laser has a tolerance. 4. The modular gas laser according to claim 2, wherein said duct and said hole have a circular cross section. 5. The modular gas laser according to claim 2, wherein a gas tight seal is provided between the duct and the electrode plate. 6. The modular gas laser according to claim 4, wherein a gas tight ring-shaped seal is provided between said duct and said electrode plate. 7. A first sleeve having an inner end supported by said electrode plate and a free outer end and enclosing said core, said core being connected to said high voltage electrode. And a threaded free outer end extending beyond the free end of the sleeve, the nut being screwed onto the threaded end of each of the cores and pulling the cores so that the sleeves are attached to the electrode plate. 7. The modular gas laser according to claim 6, wherein the core is pressed and tension is applied to the core. 8. The high voltage electrode further includes first and second corona pre-ionizers disposed proximate both edges of the high voltage electrode, the pre-onizer comprising a conductive core and a tubular insulator surrounding the conductive core. The modular gas laser according to claim 1, comprising: 9. The modular gas laser according to claim 7, further comprising a shadow plate inserted between the gas discharge gap and an insulator element of each of the ducts. 10. The modular gas laser according to claim 9, wherein the shadow plate is inserted between the high-voltage electrode and a first end of the core of each duct. 11. The high voltage duct extends through a wall of the tube, the duct comprising a first end connected to the high voltage electrode and a second end located outside the tube.
The insulator element is located around the high voltage duct and insulates the duct from a metal part of the tube; and the modular gas laser is configured to insulate the discharge gap from the discharge gap. A shadow plate inserted between the body elements; a circulating means disposed in the tube; a first laser optical element disposed at one end of the discharge gap; A second laser optical element disposed at a side end of the gas laser. 12. The electrode, the shadow plate, the insulator element, and the high voltage duct form a discharge unit that is assembled together and removably mountable, wherein the electrode comprises the discharge unit. 12. The modular gas laser according to claim 11, wherein the gas lasers are adjustable relative to each other when removed from the tube. 13. The modular gas laser according to claim 11, wherein said shadow plate is inserted between said high-voltage electrode and said first end of said high-voltage duct. 14. The modular gas laser according to claim 11, wherein said shadow plate includes an edge bent toward said insulator element. 15. The module of claim 11, wherein the shadow plate has a flow guiding shape configured to guide gas flowing across the surface into the discharge gap. Type gas laser. 16. The pipe according to claim 16, further comprising a circulating means disposed in the pipe, and a dust removing unit mounted along the cylindrical inner wall of the pipe. The modular gas laser according to claim 1, wherein a bypass stream that is a part of the stream passes through the dust removing unit. 17. The modular gas laser according to claim 16, wherein said dust removing unit includes an elongated partition wall having a substantially circular central section extending substantially parallel to said cylindrical inner wall. 18. The dust removal unit includes an elongated U-shaped channel extending parallel to the electrode, and two opposing walls of the U-shaped channel are perforated to direct the direction of the bypass gas flow in the dust removal unit. 17. The modular gas laser according to claim 16, wherein the gas laser is disposed substantially transversely. 19. The modular gas laser according to claim 18, wherein the dust removal unit includes at least one high-voltage wire extending between two walls of the U-shaped channel. 20. The cylindrical inner wall of the tube has a circular cross-section, the gas discharge unit extending along one side of the cylindrical wall, while the dust removing unit is opposite the cylindrical wall. 17. The modular gas laser of claim 16, wherein the gas laser extends along a side. 21. The tube has a first end wall at one end and a second end wall at the other end to define a cavity for containing the laser gas. A laser path axially aligned with the gas discharge gap; and a first side disposed within the laser path and exposed to the cavity formed by the tube. The first with
The high voltage comprising: a laser optical element; a first end connected to the high voltage electrode; and a wire loop electrically connected to a second end of the high voltage core. And a dust removing unit including a duct, wherein the wire loop is inside the tube near the first side of the first optical element, and the resonance path is the wire. The modular gas laser according to claim 2, wherein the wire loop is mounted on the laser tube so as to pass through the loop so as to pass through the resonance path. 22. An optical element selected from the group consisting of a completely reflective mirror, a partially transmissive and partially reflective mirror, and a completely transmissive window. 22. The modular gas laser according to claim 21, comprising: 23. The first optical element is mounted on the first end wall and is a fully reflective mirror, a partially transmissive and partially reflective mirror, and a completely transmissive mirror. 22. The modular gas laser according to claim 21, comprising an optical element selected from the group consisting of: 24. The apparatus further comprising a second optical element disposed in the laser resonance path and mounted on a second end wall of the laser tube, wherein the second optical element is formed by the tube. Having a first side exposed to the cavity, wherein the second optical element is a fully reflective mirror, a partially transmissive and partially reflective mirror, and a fully reflective mirror. Selected from the group consisting of transmissive windows, wherein the wire loop is proximate the first side of the second optical element, inside the tube, and wherein the resonance path passes through the wire loop. A second dust removal unit attached to the laser tube such that a wire loop is disposed across the resonance path;
24. The modular gas laser according to claim 23, wherein: 25. The tube has a first end wall at one end and a second end wall at the other end to define a cavity for containing the laser gas. An end wall including a port, comprising an optical axis extending longitudinally through the tube and passing through the port, and a mounting structure mounted on a first end wall of the tube; The mounting structure includes an optical element receiving surface and an opening extending through the receiving surface, wherein the opening is disposed transversely to the optical axis, and wherein the port and the light are arranged such that the optical axis passes through the opening. Aligned with the axis, the modular gas laser further includes an optical element, a tubular grip portion, and a tubular extraction portion connected to one end of the tubular grip portion and having a smaller diameter than the tubular grip portion; Above tubular grip An optical element holder adapted to grip a periphery of the optical element; and an optical element holder slidably and rotatably carried on the tubular extraction portion and removably engaged with the mounting structure. A holder that secures the optical element to the receiving surface and forms a gas tight seal therebetween.The optical element is disposed so as to cross the optical axis, and the optical axis is the optical element. The modular gas laser according to claim 1, wherein the modular gas laser is adapted to impinge upward. 26. The modular gas laser according to claim 25, wherein the holder is rotatable about a common axis in the holder, and rotation of the holder rotates the optical element. . 27. The retainer can be loosened without completely disengaging from the mounting structure,
26. The module of claim 25, wherein the holder is rotatable about a common axis within the holder when the holder is loosened, and rotation of the holder rotates the optical element. Gas laser. 28. The optical device, wherein the optical element is a completely reflective mirror,
26. The modular gas laser of claim 25, wherein the gas laser is selected from the group consisting of a partially transmissive and partially reflective mirror and a completely transmissive window. 29. The method according to claim 25, further comprising a catch disposed on an outer surface of the tubular extraction portion opposite an end connected to the grip portion. Modular gas laser. 30. The gripping portion includes a tubular clip for receiving the optical element, and a stop provided on an inner surface of the tubular clip, wherein the stop holds the optical element within the tubular clip. 26. The modular gas laser according to claim 25, wherein: 31. The flexible tube element includes a flexible tube element, the flexible tube element having a base end, an optical element receiving end, and an optical element receiving surface within the flexible tube element proximate to the receiving end. 26. The modular gas laser of claim 25, including a flexible section inserted between said base end and said receiving surface. 32. The base end is hermetically sealed to the first end wall around the port such that an optical axis of the laser passes through the flexible tube element. 32. The modular gas laser according to 31. 33. The tube has a first end wall at one end and a second end wall at the other end, the tube defining a cavity for containing a laser gas, the first end wall comprising: The wall includes a port, the modular gas laser further extends longitudinally through the tube and passes through the port, a rigid support structure including an aperture, and an optic mounted in the aperture. An element, and first, second, and third adjustable mounting devices for mounting the support structure to first, second, and third mounting points on the tube, respectively, wherein the mounting point is Wherein the rigid support structure is spaced from the laser tube by substantially the same amount as the dimensional change in the laser that occurs during operation of the laser; the rigid support structure is spaced from the laser tube; The optical element is arranged so as to cross the optical axis. And being aligned with the optical axis, the first, second, and third adjustable mounting devices are adapted to change an angular position of the optical element with respect to the optical axis. The modular gas laser according to claim 1, wherein: 34. The support structure includes a first arm and a second arm mounted on the first arm, wherein the first and second arms are at an angle. 34. The modular gas laser according to claim 33, wherein: 35. The method according to claim 35, wherein the first and second arms are attached to each other at an end portion of the arm, and the adjustable attachment device is located at the end portion of the arm. A modular gas laser according to claim 34. 36. Each of the adjustable mounting devices is inserted between a first threaded end, a second threaded end, and the first and second threaded ends. A first threaded end slidably received in a bore in the support structure and a second threaded end in the laser tube at one of the attachment points. An implanted bolt mounted; a coil screw having a first end and a second end slidably carried on a body portion of the implantable bolt; and on the first threaded end. An adjusting nut screwed into the nut; and the support structure is slidably inserted between the adjusting nut and a first end of the coil spring. The support structure may be a second of the studs.
34. The modular gas laser according to claim 33, wherein the bias is moved away from the threaded end of the to adjust nut toward the adjusting nut. 37. The stud further includes a spring stop on the body portion, wherein the spring stop is disposed on the body portion proximate a second threaded end of the stud, and The second end of
37. The modular gas laser according to claim 36, wherein said coil spring strikes said spring stop so as to be inserted between said spring step and said support structure. 38. The flexible tube element further comprising: a flexible tube element, wherein the flexible tube element includes a base end, an optical element receiving end, an optical element receiving surface in the flexible tube element proximate the receiving end, and the base. A flexure section inserted between the end and the receiving surface, wherein the base end has a first end around the port such that an optical axis of the laser passes through the flexure tube element. The optical element receiving end is engaged with an opening wall in the support structure, the optical element is received by the optical element receiving surface in the flexible tube, and the optical element is The modular gas laser according to claim 33, wherein a hermetic seal is formed between the gas laser and the optical element receiving surface.