Abstract: Flange for a vacuum apparatus comprises a housing to be connected to the vacuum apparatus defining an opening wherein the opening has rectangular narrow shape. The flange further comprises a metal seal arranged around the opening to create a vacuum tight seal.

Abstract: A carbon dioxide gas-discharge slab-laser is assembled in a laser-housing. The laser-housing is formed from a hollow extrusion. An interior surface of the extrusion provides a ground electrode of the laser. Another live electrode is located within the extrusion, electrically insulated from and parallel to the ground electrode, forming a discharge-gap of the slab-laser. The electrodes are spaced apart by parallel ceramic strips. Neither the extrusion, nor the live electrode, include fluid coolant channels. The laser-housing is cooled by fluid-cooled plates attached to the outside thereof.

Abstract: A carbon dioxide gas-discharge slab-laser is assembled in a laser-housing. The laser-housing is formed from a hollow extrusion. An interior surface of the extrusion provides a ground electrode of the laser. Another live electrode is located within the extrusion, electrically insulated from and parallel to the ground electrode, forming a discharge-gap of the slab-laser. The electrodes are spaced apart by parallel ceramic strips. Neither the extrusion, nor the live electrode, include any direct fluid-cooling means. The laser-housing is cooled by fluid-cooled plates attached to the outside thereof.

Abstract: A CO2 gas flow laser with multiple discharge modules places acoustic baffles between the discharge modules to suppress shock waves and ions passing between the discharge modules such as may disrupt the optical path of the laser. A catalyst may be placed in a center of a toroidal recirculation chamber of the laser and may have integrated filters to prevent catalyst particulates from coating the chamber optical windows.

Abstract: The present invention provides a polarization dependency-free, gain-saturated high function semiconductor optical amplifier and optical module at industrially low cost. The gist of the present invention is to structurally separate the optical signal propagating waveguide from another optical waveguide which serves as a lasing optical cavity for optical amplification in such a manner that the two optical waveguides are formed in the same plane but not parallel to each other.

Abstract: A system that transmits amplitude modulated data in a wavelength-encoded format and then uses a wavelength-sensitive receiver to convert the received optical signal back to the original amplitude modulated data. This system enables transmission of optical signals that are less sensitive to attenuation and attenuation changes. This system is applicable to data in digital, multilevel, or analog formats.

Abstract: A laser includes a deformable tube holding an electrode assembly that includes conformable spacers. The spacers are deformed by compression of the tube into good surface contact with the electrodes and the tube walls, thereby providing the necessary path for heat removal from the plasma in order to maintain the required operating temperature for adequate performance of the laser.

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: An optically-pumped laser having a gain medium configured to provide a low loss, three-dimensional integrated optical pump cavity that substantially confines optical pump radiation within the lasing volume, which is particularly useful for efficiently pumping solid state gain media that has low pump dopant concentration. The integrated pump cavity includes a plurality of boundaries contiguous with the gain medium. An optical pump source such as a laser diode array supplies optical pump radiation that is input into the gain medium through one or more pump cavity windows with a propagation direction transverse to a laser axis defined through the gain medium. In some embodiments, an optical surface is situated opposite the window to approximately recollimate the input pump radiation. The optical pump cavity may be designed to concentrate the optical pump radiation and approximately uniformly pump the entire volume of the lasing medium.

Abstract: A frequency modulated laser comprises a laser cavity in which the gain section of the laser cavity is imbedded within a phase modulation section of the cavity. The laser cavity further comprises electrically-sensitive material, so that an electric field applied across the laser cavity changes the index of refraction within the laser cavity according to the magnitude of the change in the electric field. Uniformly and simultaneously changing the index of refraction along the laser cavity length modulates the frequency of the laser light produced within the laser cavity. The upper bound of the frequency modulation is limited by the propagation time for the electric field to cross the laser cavity.

Abstract: A preionization device for a gas laser comprises an internal preionization electrode having a dielectric housing around it and an external preionization electrode displaced from the dielectric housing by a small gap. The dielectric housing includes two cylindrical regions of differing outer radii of curvature. An open end of the housing has a larger radius of curvature than the other end which is closed. The internal electrode connects to circuitry external to the discharge chamber via a conductive feedthrough which penetrates through the housing. The external circuitry prevents voltage oscillations caused by residual energy stored as capacitance in the dielectric housing. The external preionization electrode, which is connected electrically to one of the main discharge electrodes, is formed to shield the internal preionization electrode from the other main discharge electrode to prevent arcing therebetween.

Abstract: An excimer or molecular fluorine laser includes one or more sliding surface discharge preionization units each including an elongated preionization electrode spaced from one or more associated preionization electrodes by an elongated dielectric within the discharge chamber. The dielectric includes a sliding discharge surface at a long axis, or side, surface of its cross-section substantially facing the discharge volume of the laser. A portion of each of the elongated and associated preionization electrodes conductively contacts a surface of the dielectric portion preferably at a cross-sectional short axis, or top or bottom, side of the dielectric. A significant area of the surface of at least one, and preferably both, of the elongated and associated electrodes contacts the corresponding surface of the dielectric such that the contact area is substantially larger than the area of the sliding discharge surface.

Abstract: The present invention provides a novel and improved technique for achieving a combined RF-DC gas discharge in the optical cavity of the gas laser. The combination of the fast pre-ionization with the transverse RF discharge and the high power excitation with the highly-efficient longitudinal DC discharge allows for a high-speed laser gain modulation of the active medium of the high-power gas laser. At the same time, the all-metal electrode system allows for a very compact, reliable and low cost design of the gas laser.

Abstract: A solid state laser includes a high absorption coefficient solid state gain medium such as Nd:YVO4 that is side pumped with a semiconductor laser diode array. The resonant cavity of the solid state laser is positioned so that the TEM00 mode is spaced from the face of the laser through which the laser is pumped by a distance sufficient to reduce diffraction losses but sufficiently near to allow coupling of pump light into the gain mode. The gain medium, the doping level of the gain medium, and the operating temperature of the pump laser are selected to efficiently couple pump light into the gain mode. The pump laser is positioned to side pump the gain medium without collimating or focusing optics between the pump laser and the face of the gain medium. A gap between the pump laser and the gain medium is empirically selected to match the angular extent of the pump laser output light to the height of the gain mode at the position of the gain mode fixed to optimize coupling and diffraction losses.

Abstract: A method and surgical technique for corneal reshaping and for presbyopia correction are provided. The preferred embodiments of the system consists of a scanner, a beam spot controller and coupling fibers and the basic laser having a wavelength of (190-310) nm, (0.5-3.2) microns and (5.6-6.2) microns and a pulse duration of about (10-150) nanoseconds, (10-500) microseconds and true continuous wave. New mid-infrared gas lasers are provided for the corneal reshaping procedures. Presbyopia is treated by a method which uses ablative laser to ablate the sclera tissue and increase the accommodation of the ciliary body. The tissue bleeding is prevented by a dual-beam system having ablative and coagulation lasers. The preferred embodiments include short pulse ablative lasers (pulse duration less than 200 microseconds) with wavelength range of (0.15-3.2) microns and the long pulse (longer than 200 microseconds) coagulative lasers at (0.5-10.6) microns.

Abstract: In an apparatus and method for generating high power laser radiation, the geometry of the resonant laser cavity defines a fundamental spatial or transverse cavity mode. A gain medium is disposed within the resonant cavity and an energy source energizes the gain medium within a first volume. This causes spontaneous and stimulated energy emission to propagate in the gain medium in a direction transverse to the fundamental cavity mode. The transverse emission in turn optically pumps a second volume of the gain medium about the first volume. When the intensity of the emission is sufficiently high, inversion and gain are produced in the second volume. By optimizing the geometry of the cavity such that the fundamental cavity mode is coupled to both the first and the second volumes encompassing the first pumped volume, the transversely-directed energy of the first volume which would otherwise be wasted is instead captured by the fundamental beam, improving the overall power efficiently of the laser.

Abstract: An apparatus for and a method of stabilizing the laser power and frequency of a radio frequency excited laser, which are adapted to lock the laser power and frequency of the laser at the vertex of a laser gain curve using an optogalvanic effect generated from the laser itself, thereby stabilizing the laser power and frequency without requiring any specific unit to be arranged inside or outside a cavity of the laser. A capacitor is coupled to a radio frequency inlet of the radio frequency discharge tube. The capacitor serves to induce a part of radio frequency energy, introduced into the radio frequency discharge tube, toward a detector, so that the optogalvanic signal is measured, based on the induced signal, after removing radio frequency components from the induced signal by the detector, thereby enabling a measurement of a variation in input radio frequency energy caused by the optogalvanic effect.

Abstract: A laser oscillation apparatus includes: a laser cavity unit for generating laser light by being provided a voltage and optically amplifying the generated light by means of a pair of mirrors; and a DC power source for supplying the voltage required for generating the laser light to a pair of discharge electrodes of the cavity unit. Each of a cathode and an anode of the DC power source is grounded via a grounding resistor.

Abstract: A pair of elongated, parallel electrodes (91,92) are insulatively mounted within a tubular housing (111) filled with a laser gas mixture between an arrangement of reflective optical elements (120,150) sealingly mounted at each end of the housing. The electrodes form a rectangular gas discharge area (40) the minimum spacing (A) between which is the diameter of the fundamental free-space mode of the stable, laser resonator (17) formed in the gap when the electrodes are rf excited (13). A multi-pass optical configuration (30,50) uses the full width (B) of the active medium to produce a high power, compact laser (10,200). Deformable support rings (97) are compressed to push the electrodes apart against small cylindrical spacers (99) abutting the inner walls of the housing to maintain the electrodes' spatial relationship. The rf feeds (103) sealingly (112) connected to the electrodes through the housing without disturbing the uniform distribution of forces on the electrodes.

Abstract: A microwave excited laser using a sealed CO2 gas mixture for the laser medium. The laser has means for producing a uniform discharge throughout the length of the laser by using a plurality of actuators that adjust the electrical field along a deformable waveguide. The microwave waveguides are dimensioned so that the electric field is operating at or just above cut-off. A terminating cavity maintains gas discharge throughout the full length of the laser.

Abstract: A pair of elongated, parallel electrodes (91,92) are insulatively mounted within a tubular housing (111) filled with a laser gas mixture between an arrangement of reflective optical elements (120,150) sealingly mounted at each end of the housing. The electrodes form a rectangular gas discharge area (40) the minimum spacing (a) between which is the diameter of the fundamental free-space mode of the stable, laser resonator (17) formed in the gap when the electrodes are rf excited (13). A multi-pass optical configuration (30,50) uses the full width (b) of the active medium to produce a high power, compact laser (10,200). Deformable support rings (97) are compressed to push the electrodes apart against small cylindrical spacers (99) abutting the inner walls of the housing to maintain the electrodes' spatial relationship. The rf feeds (103) sealingly (112) connected to the electrodes through the housing Without disturbing the uniform distribution of forces on the electrodes.

Abstract: A gas laser having a housing including a discharge region that contains a lasing gas medium, a pair of DC electrodes having primary surfaces facing toward the discharge region, the primary surfaces being arranged in substantially parallel planes, and a pair of RF electrodes having secondary surfaces facing toward the discharge region, the secondary surfaces being in substantially parallel planes with the secondary surfaces being arranged substantially orthogonal to the primary surfaces. The gas laser also has an RF power source connected between said pair of RF electrodes and selectively generating an RF discharge in the discharge region, and a DC power source connected between said pair of DC electrodes and selectively generating a DC discharge in the discharge region.

Abstract: A gas laser consisting of a single elongated piece of dielectric material (1), with two hermetically sealed parallel elongated chambers (2) and (3), and an opening (4) connecting the two chambers. One of the elongated chambers (2) is of a cross section suitable for confining a laser gas discharge. The other elongated chamber (3) is a reservoir for laser gas, which also functions to dampen the unwanted acoustic waves generated by the laser gas discharge and as a means of extending the operating lifetime of the laser gas. The opening connecting the two elongated chambers serves to dampen the acoustic waves generated by the laser gas discharge traveling the length of the elongated laser chamber and to stop unwanted low angle wall reflections of laser light energy traveling at a slight angle to the length of the laser chamber.

Abstract: A light source including a gaseous medium which is excited to a light-emitting state by means of a microwave electromagnetic field, wherein the electromagnetic field is generated by circularly polarised microwave radiation. A preferred form of the invention is a laser.

Abstract: A laser device is capable reducing fluctuation of the beam width of the output laser beam due to abrasion of its discharge electrodes. A part of the contour shape of a section perpendicular to the longitudinal axis of the chamber of the laser device in at least one of the electrodes, which part confronts the other one of the electrodes, has a shape of a circular arc having a predetermined radius. The width of at least one of the two electrode may be substantially equal to the width of electric discharge taken place between the electrodes. Further, a conductor member may be disposed on each side of the electrode along its longitudinal axis to reduce electric field strength therearound.

Abstract: This invention is an improvement on U.S. Pat. No. 4,755,999, titled, "Laser Apparatus Utilizing a Magnetically Enhanced Electrical Discharge." That patent describes a method of forming a thin, flat discharge (slab discharge) bounded by two facing surfaces where a magnetic field is oriented perpendicular to the surfaces. This invention teaches that it is possible to improve the stability of the slab discharge by adding an AC electric field perpendicular to the facing surfaces.

Abstract: A laser head comprising a tube having a wall with the configuration of a hollow cylinder. A first ring flange extends radially generally outwardly of the tube wall at one end and is connected to the tube by a single continuous weld. A second plate flange is disposed at the same end and extends generally axially of the first flange. The first flange is coupled to the second flange and sandwiches a metal gasket therebetween to form a pressure seal. An electrode assembly is mounted to the second plate flange and at least one high voltage discharge feed extends through the wall of the tube to energize the electrode assembly. The tube is formed of a homogeneous metal that is free of any surface plating and is less reactive with Halogen gas than pure aluminum. In an associated method, the interior surface of the tube is polished to reduce the surface area and inhibit the entrapment of water vapor.

Abstract: A gas laser device includes a high frequency power source for generating a high frequency output voltage and a pair of electrodes positioned sandwiching a discharge gap through which laser gas circulates. The pair of the electrodes are connected to the high frequency power source for applying the high frequency output voltage across the electrodes to achieve discharge in the discharge gap and to thereby generate laser light. Each of the electrodes includes an electrode element, a capacity coupling control element provided on either side of the electrode element, and a dielectric shell. The dielectric shell surrounds the electrode element and the capacity coupling control element, therefore the discharge occurs between the dielectric shells of a pair of the electrodes. The dielectric constant of the capacity coupling control means is lower than that of the dielectric shell.

Abstract: An interface module (10) for transverse energy input to dye laser modules is provided particularly for the purpose of delivering enhancing transverse energy beams (36) in the form of illumination bar (54) to the lasing zone (18) of a dye laser device, in particular to a dye laser amplifier (12). The preferred interface module (10) includes an optical fiber array (30) having a plurality of optical fibers (38) arrayed in a co-planar fashion with their distal ends (44) receiving coherent laser energy from an enhancing laser source (46), and their proximal ends (4) delivered into a relay structure (3). The proximal ends (42) of the optical fibers (38) are arrayed so as to be coplanar and to be aimed generally at a common point. The transverse energy beam array (36) delivered from the optical fiber array (30) is acted upon by an optical element array (34) to produce an illumination bar (54) which has a cross section in the form of a elongated rectangle at the position of the lasing window (18).

Abstract: This invention relates to a transverse discharge pumping type pulse laser oscillating device including an electron capturing gas, especially to the configuration of preliminary ionization electrodes (4a, 4b, 8a, 8b). A transverse discharge exciting type pulse laser oscillating device according to this invention has preliminary ionization parts such that the dominant parts of corona discharge are directed to the part between main electrodes (1,2) and the developing lengths (1) of the corona discharge are long. The long developing lengths (1) increase the quantity of emitted ultraviolet rays and the electrodes (4a, 4b, 8a, 8b) are so arranged that the air between the main electrodes (1,2) is irradiated with ultraviolet rays emitted from near the initiating regions of the corona discharge, the initiating regions emitting light whose intensity is greater than those of other regions in the corona discharges. Thereby, a homogeneous main discharge is obtained and the efficiency of the laser oscillation is improved.

Abstract: By dissipating a reverse voltage energy occurring on the pulse generation capacitor (4) of a pulse laser apparatus through the diode (11) connected in parallel with this pulse generation capacitor (4), arc or streamer becomes not occurring, and hence the lifetime of the main discharge electrodes become long and a high-repetition rate oscillation becomes possible.

Abstract: A split gain multi-mode ring laser gyroscope is disclosed having a radio frequency excitation induction coil which also serves the magnetic mode suppression system, suppressing undesirable modes of the gain curve to achieve the split gain effect. The induction coil serves as an important common component of both the gain medium excitation and mode suppression systems. The induction coil is suitably configured to carry both AC and DC signals.

Abstract: A transverse-type laser assembly is disclosed herein. This assembly defines a laser cavity containing a vapor or gaseous substance which lases when subjected to specific electrical discharge excitation between a pair of spaced-apart electrodes located within the cavity in order to produce a source of light. An arrangement located entirely outside the laser cavity is provided for inducing a voltage across the electrodes within the cavity sufficient to provide the necessary electrical discharge excitation to cause a vapor substance between the electrodes to lase.

Abstract: A transversely discharge-pumped gas laser has a discharge vessel, which encloses a laser gas and at least one pair of oppositely disposed elongated discharge electrodes which extend in a predetermined longitudinal direction and are separated by a discharge region, in which laser radiation is generated which propagates along a beam path. The beam path passes once or a plurality of times through the discharge region. The direction of the beam path of the sole pass or some or all of the multiple passes forms an angle different from zero with the longitudinal direction of the elctrodes. The angle or angles are chosen such that the quality, homogeneity of intensity profile, gain and output energy of a resulting output beam are well balanced.

Abstract: In a discharge excitation gas laser device such as an excimer laser device provided with laser medium gas and a pair of electrodes opposite to each other in a gas-tight vessel, the laser medium gas is discharge-excited while inverting the polarity of a DC pulse voltage applied to the pair of electrodes opposite to each other for every pulse. In this way distribution of atoms and ions constituting the laser medium gas in the discharge region including the neighborhood of the main electrodes is made uniform even at a high repetition rate oscillation. Thus it is possible to realize a discharge excitation gas laser device having a good stability of DC pulse discharge without increasing unnecessarily the flow speed of the laser medium gas and no lowering in the pulse energy owing to a high efficiency operation.

Abstract: A gas laser of the excimer type in which an open waveguide is employed, in which the excimer medium is moved to and through the open waveguide in a direction transverse to the optical axis. A discharge cell is defined by the upper and lower slabs of the open waveguide, and if desired, a microwave source is provided which supplies microwave energy to the discharge cell volume to excite the excimer medium and to initiate discharge.

Abstract: In order to improve a gasdynamic CO laser comprising a gas supply means supplying a laser gas, an excitation region, in which the laser gas is excited, a supersonic nozzle arranged downstream of the excitation region and having the laser gas flowing therethrough and a laser-active region which is penetrated by a resonator beam path, such that it is possible to excite the laser gas in a more optimum manner, it is suggested that the laser gas be excited in the excitation region by means of a high-frequency discharge in a high-frequency discharge region and that the high-frequency discharge region end in front of the supersonic nozzle.

Abstract: In order to improve a gasdynamic CO laser, comprising an excitation region, in which a laser gas is excited, a supersonic nozzle, through which the laser gas flows, a laser-active region penetrated by a resonator beam path and a closed laser gas circuit, in which the laser gas is cyclically conducted, such that this requires smaller pumping capacities and is therefore suitable for commercial uses, it is suggested that the supersonic nozzle be designed such that at a downstream outlet thereof the laser gas has a temperature in the region of approximately 80 to approximately 180 Kelvin.

Abstract: An electric discharge tube for a gas laser in which a laser gas flow axis and a laser oscillation optical axis are coaxial and a discharge direction of discharge pumping is perpendicular to those axes. The internal sectional form of a discharge tube (1) perpendicular to the laser oscillation optical axis is made rectangular and the internal diameter of nondischarge sections (10a, 10b) is made larger than the diagonal line of the discharge tube (1). The section of laser beams generated in a rectangular discharge region (11) becomes substantially rectangular in shape and the laser beams are externally output intact, whereby a substantially rectangular beam mode is obtained.

Abstract: Preionization is important for the generation of a homogeneous glow discharge in the gas space of a laser chamber between laser electrodes. TE type excimer lasers operate especially with X-ray preionization, for which high voltage pulses are needed. According to the present invention, the voltage pulses are obtained by means of an auxiliary circuit that includes a branch which is connected in parallel with a high voltage switch or with the laser discharge gap and which incorporates a saturable magnetic inductance and the primary winding of a high voltage pulse transformer connected in series therewith. The high voltage triggering pulses for the preionization element, which is an X-ray tube in particular, are generated in the secondary winding of the transformer. If the branch is connected in parallel with the high voltage switch it also has a series capacitor. If it is in parallel with the laser discharge gap then the branch has a shunt capacitor.

Abstract: An apparatus and method for generating high-power, high-voltage pulses for a laser having laser electrodes with an electrode path includes at least one charge unit. A pulse-generating network has an input side connected to the at least one charge unit and an output side connected to the laser electrodes. The pulse-generating network has a first branch and a second branch connected parallel to one another and connected to the laser electrodes. The first branch has a first charge capacitor with a relatively high capacitance and a magnetic switch in the form of a saturatable inductor connected in series with the first charge capacitor. The second branch has a second charge capacitor with a relatively low capacitance. A trigger branch is connected parallel to the electrode path. The trigger branch has at least one high-voltage switch and an in-series inductance.

Abstract: An asymmetric RF excited gas laser includes an elongated chamber, a first reflector and a second reflector, a first supporting mechanism, a ribbon of a metal conductor and a impedance-matching circuit. The elongated chamber is of cross-sectional dimensions suitable for confining a laser gas discharge and is formed from a dielectric material. A laser gas is disposed in the elongated chamber. The first and second reflector reflect and guide light energy from the laser gas discharge within the elongated chamber so that the light energy is optically independent of the internal walls of the elongated chamber as the light energy travels longitudinally the length of the elongated chamber. The first supporting mechanism supports the elongated chamber and forms negative electrode. The first supporting mechanism has cooling tubes and is electrically coupled to ground. The ribbon of the metal conductor forms a positive electrode which is disposed along the elongated chamber.

Abstract: A new configuration of the electrodes of a transverse discharge pumped gas laser is disclosed, in which the electrode connected to ground and the electrode connected to the main condenser bank are placed on the same plane so as to face a third electrode connected to a high impedance. There are two distinct discharge regions, one of which is the back path of the current passing through the first discharge region.

Abstract: A discharge device, especially for a gas laser, has a discharge chamber through which a gas flows at high velocity and the gas discharge burns as a steady-field discharge between an anode and a cathode lying opposite the anode as the main electrodes extending transversely of the gas flow. To obtain a high ionization rate with a low alternating-current power consumption, while at the same time pre-ionizing the entire volume of incoming gas present between the cathode and anode, at least two pre-ionizing electrodes are present, one of which is in front of the cathode and the other in front of the anode in the direction of flow, and the pre-ionizing electrodes are out of phase with one another.

Abstract: To provide more economical excitation of a high-power laser comprising a resonator having mirrors arranged in spaced, opposite relation to each other in the direction of a resonator axis and a beam path extending in both the direction of the resonator axis and a transverse direction perpendicular thereto, a gas-discharge volume permeated by the beam path and containing laser gas, and two facing wall surfaces extending substantially parallel to the resonator axis and to the transverse direction and enclosing between them and thereby delimiting the gas-discharge volume, it is propsoed that at least one wall surface be formed by a dielectric wall, that a microwave resonance structure separate from the laser gas in the gas-discharge volume be placed on the dielectric wall and have an opening facing the dielectric wall and bring about in an area of volume of the gas-discharge volume opposite the opening a microwave excitation of the laser gas, and that microwaves be introducible into the microwave resonance struct

Abstract: An excitation circuit for TE lasers serves to generate a homogeneous high pressure glow discharge between laser electrodes within a gas space of a laser chamber. A fast acting high voltage switch of a pulse forming network is a multi-channel pseudo-spark switch and is preferably integrated with the laser. The switch is formed of a parallel circuit including a number of individual pseudo-spark switches with gaps. The total multi-channel pseudo-spark switch is filled with an ionizable low pressure gas filling at a given pressure. Voltage is applied to the anode and the cathode in such a way that the resulting gas discharge is located on the left-hand branch of the Paschen curve. The switch of the excitation circuit can also be used as a separate structural element for triggering an electrical high voltage switch circuit, and also for so-called flat plane laser systems.

Abstract: A compact excimer laser, including a housing structure having a plurality of walls forming an internal laser cavity. A gas is located within the laser cavity and with the gas capable of lasing action. A pair of spaced electrodes are located within the laser cavity and form an electrical discharge area between the electrodes for stimulating gas within the discharge area to lasing action in accordance with an electrical discharge between the electrodes. One of the pair of electrodes is located along a central position within the cavity and is grounded to the housing structure. The other of the pair of electrodes is located adjacent to but spaced from one of the walls of the housing structure and with the other electrode mounted on a main insulator member.

Abstract: The invention relates to a gas laser having a discharge tube, through which the gas flows in an aixal direction and to which high-frequency electrodes are fitted externally, and having a high-frequency generator. In order to obtain a simpler construction and the smallest possible high-frequency losses, it is provided that the power output stage (12) of the high-frequency generator is disposed in the housing (1) of the laser resonator (2, 7, 8) and is directly connected to the electrodes (9, 10) via impedance adaptation elements (11).

Abstract: A gas laser comprises an optical cavity, a coaxial transmission line at least partially disposed in the optical cavity, a lasant gas disposed in the cavity, and means for transmitting at least one electrical pulse progressively along the transmission line to generate a travelling wave of ionization to pump the lasant gas.

Abstract: A method and surgical technique for corneal reshaping and for presbyopia correction are provided. The preferred embodiments of the system consists of a scanner, a beam spot controller and coupling fibers and the basic laser having a wavelength of (190-310) nm, (0.5-3.2) microns and (5.6-6.2) microns and a pulse duration of about (10-150) nanoseconds, (10-500) microseconds and true continuous wave. New mid-infrared gas lasers are provided for the corneal reshaping procedures. Presbyopia is treated by a method which uses ablative laser to ablate the sclera tissue and increase the accommodation of the ciliary body. The tissue bleeding is prevented by a dual-beam system having ablative and coagulation lasers. The preferred embodiments include short pulse ablative lasers (pulse duration less than 200 microseconds) with wavelength range of (0.15-3.2) microns and the long pulse (longer than 200 microseconds) coagulative lasers at (0.5-10.6) microns.