Abstract: Methods and apparatus are provided for cleaning and passivating laser discharge chambers with plasmas. In one embodiment, an oxygen based plasma is formed in a plasma source external to the laser discharge chamber by applying a radiofrequency signal to oxygen containing gases. The oxygen based plasma is drawn into the laser discharge chamber, where it reacts with contaminants and cleans internal surfaces. After cleaning, a fluorine based plasma is formed in the plasma source and drawn into the laser discharge chamber to passivate internal surfaces. In another embodiment, cleaning with the oxygen based plasma is not used since some level of cleaning is accomplished with the fluorine based plasma. In another embodiment, oxygen based plasmas and fluorine based plasmas are formed in the laser discharge chamber by applying a radiofrequency signal to a laser discharge chamber electrode.

Abstract: A MEMS resonator includes an annular resonator body defined by an inner radius and an outer radius, a first electrode positioned within the inner radius and spaced from the resonator body, and a second electrode positioned around the annular resonator body and spaced from the outer radius. The first electrode and the second electrode provide for capacitive drive of the resonator body and capacitive sense of the resonator body. Piezo-resistive sense and piezoelectric drive/sense techniques can also be utilized. The overall extent can be smaller than 1 cm2 in area and positioned on a supporting substrate by a plurality of anchors. The substrate can comprise an RF transceiver integrated circuit with the anchors connecting the drive electrode and sense electrode to the integrated circuit. The resonator is readily fabricated using conventional semiconductor integrated circuit fabrication techniques.

Abstract: A support unit (20a) for supporting an OPM holder (15a) so as to be vertical to the laser beam axis is disposed in the lower part of the OPM holder (15a). A rotary shaft (19) is inserted into the support unit (20a) and rotary shaft support unit (20b), and the OPM holder (15a) and DT base (17) are assembled together. Thus, a rotation support unit (200) is composed. The rotation support unit has a degree of freedom in the rotating direction of arrow (202). On the other hand, in the lower part of an RM holder (15b), a support bar (21) is provided. At the DT base (17), a rotating element (22) and a rotating element support unit (23) supporting the rotating element are composed so as to support the support bar. Thus, a slider structure (220) slidable in the optical axis direction is formed. The slider structure has a degree of freedom in the direction of arrow (222).

Abstract: The present invention provides a cylindrical slab type gas laser for generating an excellent laser beam having substantially Gaussian intensity distribution of the focussed output laser beam. For this end, a pair of cylindrical electrodes 11, 12 of different diameter are disposed vertically and concentrically. And laser medium is filled in the gap between the two cylindrical electrodes 11, 12 to define a cylindrical straight slab 1. Disposed at one end of the cylindrical top of the cylindrical straight slab 1 is a ring-shaped trick mirror M1 and also disposed at the center of the one end of the cylindrical straight slab 1 is an output mirror M2 to pass a part of the light and to reflect a part of the remaining light. On the other hand, disposed at the other end of the cylindrical straight slab 1 is a w-axicon mirror M3. The above construction eliminates the need for spacers between the two cylindrical electrodes 11, 12 which are required in a conventional gas laser.

Abstract: A gas laser comprises a pair of elongated electrodes arranged to define a discharge region between two opposing surfaces of said elongated electrodes, wherein the discharge region defines a longitudinal axis, a wide axis and a narrow axis. The gas laser further includes a lasing gas disposed in said discharge region and an excitation means for energizing the electrodes to excite the lasing gas. A first mirror is arranged in front of a first end of the pair of elongated electrodes, wherein the first mirror is spaced apart from the first end along the longitudinal axis by a first distance, and a second mirror is arranged in front of a second end of the pair of elongated electrodes. Moreover, the two opposing electrode surfaces define an electrode curvature, respectively, that is adapted such that a wave front of the a fundamental transverse radiation mode with respect to the narrow axis substantially coincides with a mirror curvature of the first mirror at the first distance.

Abstract: A gas discharge tube such as a ring laser gyroscope includes a block. A cathode has an inwardly extending foot that engages the block. Additionally, or alternatively, an insulator is arranged to inhibit shorting between plasma in the block and a flange of the cathode.

Abstract: A tangential blower for use in a gas discharge laser is provided provides improved homogeneity of laser gas flow through the discharge region of the laser. A flange which supports adjacent blower sections has an aerodynamic shape and occupies a minimal portion of the space in the inlet region of the blowers. The ends of the blower's shafts may be formed as a twice-profiled polygon which is has a non-uniform and preferably rounded geometry along its longitudinal axis where it fits into end flanges. The blades of the blower may be formed with varying thickness and radii of curvature. The blower's blades and hubs may be cast as a single piece of steel, titanium alloy, or other suitable material.

Abstract: A gas supply path structure forms a fluid path for allowing a laser gas to flow into or out of a pair of fluid inlet and outlet 11a and a laser gas is controlled to a predetermined subsonic speed at a throat portion. Gas supplies for controlling the speed of the gas are connected each to the fluid inlet and to the fluid outlet of the gas supply path structure and, together with a cooling device, compose a circulation system for controlling the speed and pressure of the laser gas at the fluid inlet and/or at the fluid outlet.

Abstract: Method and system for providing stabilization techniques for high repetition rate gas discharge lasers with active loads provided in the discharge circuitry design which may include a resistance provided in the discharge circuitry.

Abstract: An optical element holding and extraction device is provided. The device includes an optical element, an optical element holder having a tubular gripping portion and a tubular extraction portion connected at one end to the tubular gripping portion, and a retainer that is slideably carried on the tubular extraction portion. The diameter of the tubular extraction portion is less than the tubular gripping portion. In addition, the tubular gripping portion grips the peripheral edge of the optical clement. The device may be used in a variety of gas lasers, including excimer lasers.

Abstract: A gas supply path structure forms a fluid path for allowing a laser gas to flow into or out of a pair of fluid inlet and outlet 11a and a laser gas is controlled to a predetermined subsonic speed at a throat portion. Gas supplies for controlling the speed of the gas are connected each to the fluid inlet and to the fluid outlet of the gas supply path structure and, together with a cooling device, compose a circulation system for controlling the speed and pressure of the laser gas at the fluid inlet and/or at the fluid outlet.

Abstract: The invention relates to a gas discharge laser including a discharge tube (1), in which a gas is present and which has at least one aperture (19) through which a laser beam emerges or at which a laser beam is reflected. For withdrawing a partial amount of the gas contained in the discharge tube (1), at least one gas withdrawal point (9) is present, from which the withdrawn gas is supplied to a sintered filter (11) for being cleaned. The cleaned gas may be led in via at least one gas inlet point (27) in the zone of the aperture (19). The invention further relates to a method of operating a gas discharge laser, and the use of a sintered filter for cleaning gas withdrawn from a discharge tube (1) of a gas discharge laser.

Abstract: The present invention provides an injection seeded modular gas discharge laser system capable of producing high quality pulsed laser beams at pulse rates of about 4,000 Hz or greater and at pulse energies of about 5 to 10 mJ or greater for integrated outputs of about 20 to 40 Watts or greater. Two separate discharge chambers are provided, one of which is a part of a master oscillator producing a very narrow band seed beam which is amplified in the second discharge chamber. The parameters chamber can be controlled separately permitting optimization of wavelength parameters in the master oscillator and optimization of pulse energy parameters in the amplifying chamber. A preferred embodiment is a F2 laser system configured as a MOPA and specifically designed for use as a light source for integrated circuit lithography. In this preferred embodiment, both of the chambers and the laser optics are mounted on a vertical optical table within a laser enclosure.

Abstract: The above discussed and other drawbacks and deficiencies of the prior art are overcome or alleviated by a laser of the present invention. In accordance with the present invention the laser comprises a housing defining a plurality of compartments therein, a folded waveguide disposed within the housing, the folded waveguide defining a plurality of channels having a substantially rectangular cross section for guiding a laser beam, a plurality of electrodes disposed in the plurality of compartments and juxtaposed along opposite surfaces of the waveguide and at least one power supply connected to the plurality of electrodes. The channels having a prescribed width to height ratio for a prescribed channel length for a given Fresnel number. At least one optical housing is provided. The optical housing is mounted to the laser housing, the optical housing including a plurality of beam turning mechanisms disposed within a plurality of compartments accessible for adjusting the beam turning mechanisms.

Abstract: A dedusting unit for a laser optical element is provided. The dedusting unit comprises a high-voltage duct comprising a high-voltage conducting core having a first end and a second end and an insulator element disposed around the core. The first end of the core is connectable to a high voltage power supply and the second end of the core is electrically connected to a wire loop. The dedusting unit may be used in connection with a variety of gas lasers. In use, the dedusting unit is mounted to the laser tube so that the wire loop is disposed inside the gas laser tube in proximity to an optical element to be protected from dust. The dedusting unit is further mounted so that the wire loop is transverse to the resonating path of the laser light within the laser tube so that the resonating laser light may pass through the wire loop without being obstructed by the wire loop. A method for installing the dedusting unit to protect a laser optical element in a gas laser is also provided.

Abstract: An excimer or molecular fluorine laser system includes a discharge tube filled with a gas mixture, multiple electrodes within the discharge tube and connected to a discharge circuit for energizing the gas mixture, a resonator for generating a laser beam, and at least one window structure including a first window and a second window. The first window initially seals the discharge tube and transmits the beam. The second window is initially unexposed to the gas mixture. The window structure is configured such that the second window is movable into position for sealing the discharge tube and transmitting the beam when the first window becomes contaminated.

Abstract: A support unit (20a) for supporting an OPM holder (15a) so as to be vertical to the laser beam axis is disposed in the lower part of the OPM holder (15a). A rotary shaft (19) is inserted into the support unit (20a) and rotary shaft support unit (20b), and the OPM holder (15a) and DT base (17) are assembled together. Thus, a rotation support unit (200) is composed. The rotation support unit has a degree of freedom in the rotating direction of arrow (202). On the other hand, in the lower part of an RM holder (15b), a support bar (21) is provided. At the DT base (17), a rotating element (22) and a rotating element support unit (23) supporting the rotating element are composed so as to support the support bar. Thus, a slider structure (220) slidable in the optical axis direction is formed. The slider structure has a degree of freedom in the direction of arrow (222).

Abstract: Internal mirror sputtering metal ion lasers are disclosed which employ laser mirrors and a resonator internal to and integral with the laser plasma tube. Preferred lasers use silver, copper, gold and other metals individually or in combination as optically active materials and buffer gases of helium, neon, argon and other noble gases. Laser mirrors are utilized to enhance or reject selected combinations of emission wavelengths. Because of the rapid response time of these lasers, they may be employed as quasi-CW devices with laser output pulse widths ranging from a few microseconds to hundreds of microseconds and with very low input power ranging from a few watts to about 500 watts. The disclosed lasers approach the size, weight, power consumption, and cost of a helium-neon laser while providing quasi-continuous output up to hundreds of milliwatts at a wide range of wavelengths from about 200nm in the deep ultraviolet to about 2000nm in the middle infrared.

Abstract: Electric field easing members (corona rings) for easing concentration of electric fields caused at edges of a core are disposed between the core and a winding to form a gap so to allow the presence of a cooling medium (insulating oil) between the top and bottom surfaces of the core and the electric field easing members. Thus, pressboards between the core and the electric field easing members become unnecessary, a wire-wound apparatus can be prevented from having a short service life due to the degradation of the pressboards, and the pressboards can be made to have a long service life because the electric field easing members are not heated by thermal conduction from the core.

Abstract: A gas drawing/refilling and sealing structure for a laser gas storage container of the present invention includes a sealed container and a blocking member, wherein the body of the container is provided with a gas passage having a gas inlet end and a blocking end. The gas passage is further provided with a communicating section to make connection of the gas passage to the container. The blocking member is mounted on the blocking end, gas is drawn out of or injected into the container via the gas inlet end when the gas inlet end is opened; the gas is cut off when the gas inlet end is closed, and the container is sealed at the same time. Thereby, manufacturing and test of the laser equipment can be more convenient, and the superiority of products can be increased.

Abstract: A spiral-type guide member having a spiral channel extending about an open center portion is provided adjacent the gas inlet end of the laser discharge tube of a gas laser assembly. This guides the entering gas stream about the periphery of the laser discharge tube to improve the distribution of the power of the laser beam over the cross section of the laser discharge tube to the discharge tube of the laser beam 113 is provided for the laser gas in the feed line 123, through which at least part of the laser gas is fed to the laser-discharge tube 103.

Abstract: One optical base is provided on each side of a housing that houses a laser oscillator. Optical parts of an optical resonator are fixed to the optical bases. The optical bases are fixed to each other, independently from the housing, by supporting rods. A plate spring and two dampers fix the respective optical base to respective end of the housing. The plate spring bends in the direction of the laser beam when the housing deforms. The damper attenuates oscillation generated due to the displacement of the housing.

Abstract: A CO2 laser utilizing combination of direct current (DC), radio frequency (RF) discharges together with an unstable resonator is disclosed. The combined use of the combination of DC and RF discharges in the laser apparatus allows to provide high power output radiation within a relatively compact design of the apparatus. Consequently, the laser operating efficiency is increased, with a significant lowering of required excitation voltages, and a substantial reduction in excitation hardware. The laser apparatus of the present invention may have durable and reliable construction that is relatively easy and cheap in manufacturing.

Abstract: A gas laser and a dedusting unit thereof are provided. The gas laser comprises a tube containing a gas mixture including a laser gas and preferably a buffer gas. The tube preferably comprises a cylindrical inner wall. A discharge unit is inserted into the tube and has two elongated electrodes defining an electrical gas discharge gap therebetween for providing an electric gas discharge between said electrodes to generate laser light. A circulation means is included in the tube for generating a gas flow within the tube that passes through the discharge gap. A dedusting unit is mounted along the inner cylindrical wall of the tube in such a manner that only a bypass flow which is a part of the gas flow within the tube passes through the dedusting unit.

Abstract: An orifice (254) is disposed near the junction of a discharge tube (1) and a laser gas lead-in pipe (242). A laser gas relay pipe (244) is disposed so as to allow the laser gas to flow parallel in the same direction as or in the reverse direction to the flowing direction of laser gas in the discharge tube (1). The orifice (254) includes a portion for impeding flow of laser gas, and plural holes for passing laser gas, and at least one of the holes is deviated from the center. The total area of the holes summing up the area of the plural holes provided in the orifice (254) is at a rate of 0.5 to 0.8 to the sectional area of the discharge tube. The plural holes of the orifice (254) are nearly circular, and the diameter of each hole is smaller than the radius of the orifice.

Abstract: A gas laser device including a dust filter with which a flow rate of laser gas flowing between discharge electrodes is approximately uniform in a longitudinal direction of the discharge electrodes without a variation with time is provided. For this purpose, the gas laser device includes a laser chamber (2) containing laser gas, a pair of discharge electrodes (5, 5) disposed inside the laser chamber (2) to face to each other for exciting a laser medium by discharge to thereby oscillate laser light, a fan (14) for circulating the laser gas to send the same to an area between the discharge electrodes (5, 5), and a dust filter (12) for eliminating dust generated inside the laser chamber (2), and has a configuration in which a filter inlet port (15), which is formed in an inner wall (2A) of the laser chamber (2) and guides the laser gas into the dust filter (12), is formed to be approximately vertical to the inner wall (2A) of the laser chamber (2).

Abstract: An efficient and practical means and method is provided for monitoring the F2 concentration in an F2 excimer laser. The F2 concentration is monitored by measuring the concentration F atoms and more specifically by measuring the amount of red laser light emitted during discharge. The amount of red laser light emitted during discharge is a function of the concentration of F atoms because such red laser light is emitted by excited F atoms. There is also a relationship between the concentration of F atoms and the concentration of molecular F2 in the discharge chamber. Accordingly, the concentration of F2 gas may be monitored by measuring the amount of red laser light emitted during discharge.

Abstract: A gas laser discharge unit is provided. The discharge unit includes an elongated electrode plate having a plurality of spaced-apart holes therein and a plurality of coaxial high voltage ducts. Each duct extends through one of the holes in the electrode plate and includes a central conductive core and an insulator element arranged around the core to electrically insulate said core from the electrode plate. An elongated high voltage electrode is electrically connected to the cores of the ducts. In addition, an elongated ground electrode is positioned to oppose the high voltage electrode and form a gas discharge gap therebetween. The ground electrode is electrically connected to the electrode plate. The gas laser discharge unit may be removably mounted as a module into a gas laser tube, such as an excimer laser tube.

Abstract: An efficient F2 laser is provided with improvements in line selection, monitoring capabilities, alignment stabilization, performance at high repetition rates and polarization characteristics. Line selection is preferably provided by a transmission grating or a grism. The grating or grism preferably outcouples the laser beam. The line selection may be fully provided at the front optics module. A monitor grating and an array detector monitor the intensity of the selected (and unselected) lines for line selection control. An energy detector is enclosed in an inert gas purged environment at slight overpressure. A blue or green reference beam is used for F2 laser beam alignment stabilization and/or spectral monitoring of the output laser beam. The blue or green reference beam advantageously is not reflected out with a atomic fluorine red emission of the laser and is easily resolved from the red emission.

Abstract: An electrode arrangement for a gas laser is provided. The electrode arrangement includes an elongated high voltage electrode, an elongated ground electrode disposed adjacent to the high voltage electrode, a discharge gap between the two electrodes an insulator element, a high voltage conductor having a first end connected to the high voltage electrode and extending through the insulator element, and a shadow plate interposed between the discharge gap and the insulator element. The electrode arrangement may be employed in a variety of gas lasers, including excimer lasers.

Abstract: A gas laser gas has an elongated cavity in which are disposed a first elongated electrode tube having an inner diameter, and a second elongated electrode tube disposed coaxially within the first electrode tube and having an outer diameter smaller than the inner diameter of the first electrode tube and spaced therefrom so as to provide a gas discharge chamber therebetween. The second electrode tube provides a gas exit chamber therewithin, and the first electrode tube is spaced from the wall of the cavity to provide a gas entry chamber thereabout. The electrode tubes permit gas to flow therethrough from the gas entry chamber to the gas exit chamber. The electrodes may be formed from a gas permeable material such as sintered metal, or formed from a non-permeable material with openings therein. The electrodes may have coolant flowing therethrough.

Abstract: A gas discharge modular laser with beam train isolation between laser chamber module and front and rear optics which define the laser resonant cavity. Beam train isolation units isolates the beam train from atmospheric air while permitting quick and easy removal of the laser chamber without disturbing the optics of the resonant cavity. In preferred embodiments, metal bellows units are bolted at only side so that the chamber module can be removed and replaced without unbolting the bellows unit.

Abstract: An HF-excited gas laser has a laser tube of ceramic material containing a laser gas, and the tube includes a chemical component which will preclude passage therethrough of secondary radiation of a wavelength within a proscribed range which would interact with the material of the laser tube to create defects therein. The chemical component to prevent damage to the laser tube may be provided as a layer on its inside surface which is essentially impermeable to and/or reflects the secondary radiation back into the lasing gas. Alternatively, the material of the laser tube may incorporate the chemical component, preferably over the portion of the wall adjacent its inner surface.

Abstract: The present invention relates to laser devices with increased cooling capability by means of largely extended cooling surfaces contacting the laser active medium. According to the present invention there is provided a laser device comprising a large active volume in conjunction with a compact structure of the device and outputting single mode radiation. The laser device according to the present invention comprises the following features. A laser active medium, an optical resonator system defining an optical axis, exciting means for exciting said laser active medium and enabling a stimulated emission of radiation of said laser active medium, and cooling means, having first and second cooling elements arranged in spaced opposing relationship with surfaces facing each other, wherein said laser active medium is provided between said cooling elements along said optical axis.

Abstract: Reflective powder, such as barium sulfate, within a reflector chamber of a solid-state optical pumping laser is effectively isolated from coolant-water, preventing contact therewith. Degeneration of reflectors and diminution of lasing magnitude is avoided. Water seals are shielded from substantially all light from the flashlamps by a light barrier. Ultraviolet light from the flashlamps is blocked from contacting the water seals. Degradation of the seals is eliminated; and water leakage-contact with the reflective powder is prevented.

Abstract: A short cavity gas discharge laser stabilized by use of a highly reflective output coupler adjustably connected to a support isolated from the longitudinal thermal expansion of the laser enclosure. A flexible seal between the output coupler and the laser enclosure accommodates positional adjustment of the output coupler relative to the mirror to optimize performance. In one embodiment, the laser gas is contained by the enclosure and is in contact with the electrodes which divide the interior of the enclosure into two portions that provide gas ballast for the laser. In another embodiment a pair of electrodes are located adjacent to and outside of a discharge tube made of dielectric material. The laser discharge occurs in the discharge tube and the electrodes are not in physical contact with the discharge. Gas ballast is optionally provided through at least one reservoir in fluid communication with the discharge tube.

Abstract: A grating based line narrowing device for line narrowing lasers producing high energy laser beams. Techniques are provided for minimizing adverse effects of heat produced by the laser beam inside the line narrowing device.

Abstract: An electric discharge laser with fast wavelength correction. Fast wavelength correction equipment includes at least one piezoelectric drive and a fast wavelength measurement system and fast feedback response times. In a preferred embodiment, equipment is provided to control wavelength on a slow time frame of several milliseconds, on a intermediate time from of about one to three millisecond and on a very fast time frame of a few microseconds. Techniques include a combination of a relatively slow stepper motor and a very fast piezoelectric driver for tuning the laser wavelength using a tuning mirror. A preferred control technique is described (utilizing a very fast wavelength monitor) to provide the slow and intermediate wavelength control and a piezoelectric load cell in combination with the piezoelectric driver to provide the very fast (few microseconds) wavelength control.

Abstract: There is provided an electric discharge gas laser comprising a housing containing a laser gas; a rotating fan provided in the housing to circulate the gas in the housing; a bearing device for magnetically supporting a rotating shaft of the rotating, the bearing device being provided with a sensor device comprising a sensor for sensing the position of the rotating shaft to generate signals indicating the position of the rotating shaft, and a signal processor for receiving and processing the signals delivered from the sensor to output processed signals; and a control separated from the bearing device and functionally associated with the bearing device to receive the processed signals from the sensor device for controlling the bearing device on the basis of the processed signals.

Abstract: A system is provided for delivering a laser beam of wavelength less than 200 nm from a laser, such as an F2 laser or ArF laser, through a sealed enclosure sealably connected to the laser, and preferably to another housing, leading ultimately to a workpiece. The enclosure is preferably evacuated and back-filled with an inert gas to adequately deplete any air, water, hydrocarbons or oxygen within the enclosure. Thereafter or alternatively, an inert gas flow is established and maintained within the enclosure during operation of the laser. The inert gas preferably has high purity, e.g., more than 99.5% and preferably more than 99.999%, wherein the inert is preferably nitrogen or a noble gas. The enclosure is preferably sealed by a window transparent to the sub-200 nm radiation for preventing contaminants generated in the enclosure from entering the housing and contaminating surfaces therein. The enclosure is preferably made of steel and/or copper, and the window is preferably made of CaF2.

Abstract: A high power and long lifetime gas laser device suitably usable in an exposure apparatus is disclosed. The gas laser device includes a chamber for sealingly storing a laser gas therein, a discharging electrode for exciting the laser gas through electric discharging, so that laser light is outputted from the chamber, and a circulating system for circulating the laser gas within the chamber so that the laser gas passing an electric discharging region of the discharging electrode is circulated in the chamber and is returned to the electric discharging region of the discharging electrode, and a control system for controlling the circulating system so that the circulating system provides different gas circulation capacities, being different for an in-operation state in which the laser gas is excited by electric discharging from the discharging electrode and the laser light is outputted and for a stand-by state which differs from the in-operation state but in which laser light can be outputted.

Abstract: A power efficient continuous wave gas ion laser system, associated laser tube and method are described. The system uses a fixed electrical input power and a power factor corrected power supply producing an output voltage and an output current from the fixed input electrical power. A gas ion laser tube is configured for use in the system having a particular cavity length which is established as a distance between a first mirror and a second mirror for operation using the output voltage and the output current. The system may be configured to provide a light output power improvement of approximately thirty percent over prior laser systems. In one feature, a laser tube is configured for providing the improved light output power in a conventional laser head configuration such that the laser tube may directly replace laser tubes in prior installations. Existing and new laser installations may benefit.

Abstract: The invention relates to a machining head and to a process for the surface machining of workpieces by means of a laser beam, in which coating, alloying in the area close to the surface or dispersion of a peripheral zone of the base material with powder particles can be carried out using a pulverulent filler supplied. The invention is intended to make it possible to maintain, independently of direction, a virtually constant mass flow rate of the powder supplied, the intention being to form a uniform hollow powder jet.

Abstract: The present invention provides a novel metal-vapor pulsed laser capable of being manufactured without using a large-sized laser tube or an expensive discharging circuit. The output and the efficiency of the laser can be improved economically and easily. The laser includes a laser tube having a cathode and an anode. A discharging circuit induces an electric discharge in the laser tube. A grid electrode is mounted close to the cathode of the laser tube. A preliminary discharge is produced between the grid electrode and the cathode to thereby induce a main discharge.

Abstract: The gas laser oscillator having metal housings disposed near internal mirrors of the resonator for covering, for example, the external of connecting tubes partially or totally, means for detecting the micro discharge current flowing inside of the connecting tubes near the internal mirrors of the resonator, and a control circuit for controlling energy to be supplied into discharge tubes by comparing output signals output from the means for detecting the micro discharge current with reference signals. The gas laser oscillator prevents the micro discharge current from flowing in laser gas inside of the connecting tubes, thereby preventing degradation of a total reflection mirror and a partial reflection mirror defining the internal mirrors of the resonator.

Abstract: A gas laser, in particular an axial-flow CO2 gas laser, includes a resonator having a folded beam path in a first folding plane and in a second folding plane inclined at 45° thereto. At least one Z-fold of the beam path is provided in the first folding plane and at least one U-fold of the beam path is provided in the second folding plane.

Abstract: A device for detecting failures in a laser transmitting passage includes an inner tube (80) made from an optical hollow waveguide and having a first space (122) through which laser is transported, an outer tube (78) surrounding and extending along the inner tube, and a detector which recognizes a first condition in which the first space is fluidly disconnected from the second space and a second condition in which the first space is fluidly connected to the second space. The first and second conditions can be determined from a pressure, flow rate, gas concentration, ingredient of gas, or temperature in first or second space.

Abstract: There is disclosed a metal vapour laser comprising a discharge tube having a buffer gas therein and operating at high temperature, the buffer gas including a laser output power enhancing substance in an amount sufficient to substantially increase the power output of the laser. There is also disclosed a process for operating a metal vapour laser of the invention.

Abstract: The performance of an RF excited gas laser having a discharge region with a generally curvilinear orthogonal cross-section, the shorter of the two dimensions of the discharge region cross-section being the spacing between non-conductive sidewalls which collisionally cool the discharge and are rotatable for guiding laser light, is enhanced by excitation field shaping. The field shaping includes use of a non-conductive member disposed between a high voltage field establishing electrode and a sidewall of the discharge region.

Abstract: The present invention provides an electric discharge gas laser having a laser cavity in which is contained a laser gas and a fan for circulating the laser gas. The fan is supported by an active radial magnetic bearing system and driven by a brushless DC motor in which the rotor of the motor and the rotors of at least two radial bearings are sealed within the gas environment of the laser cavity and the motor stator and the coils of the bearing magnets are located outside the gas environment. No thrust bearing is provided. Axial positioning of the shaft is provided by reluctance centering produced by the at least two radial magnetic bearings and the brushless DC motor. In a preferred embodiment the motor stator is larger in the axial direction than the rotor to increase the magnetic centering effect.