Abstract: A microwave pumped excimer laser and method.

Abstract: A method for enhancing the lasing action in a chemical oxygen iodine laser wherein a gas stream having a desired reactant gas concentration profile is combined with a diluent gas concentration profile using hydrogen as the diluent gas.

Abstract: For the excitation of a discharge in a laser gas, an electrode arrangement is provided which consists of at least two elongated electrodes wound approximately in a cylindrical helical line. The double helix thus formed is arranged on or concentrically within a gas flow tube.

Abstract: A laser system having a gaseous Raman cell incorporate methane (CH.sub.4) as the Raman scattering medium. The cell includes gaseous hydrogen to prevent deposition of carbonaceous material from decomposed methane on the windows of the Raman cell.

Abstract: For an excimer laser system utilizing in a laser chamber a lasing material and a mixture of a diluent rare gas and a heavy rare gas and halogen rare gas in given percentages, there is disclosed a method and apparatus for reducing the expenditure of the rare gases by continuously evacuating the laser mixture from the laser chamber removing from the evacuated laser mixture any gaseous impurities to provide a cleaned laser mixture and thereafter feeding the cleaned laser mixture back into the laser chamber. Along with the cleaned laser mixture there is fed in a supplemental halogen gas. The gaseous impurities along with the halogen are removed by passing the gas through an elongated tube having calcium particles therein with a void fraction for a given length of tube in the range 0.30 to 0.60. Some of the ratio is obtained by providing alternate layers of calcium particles and inert, refractory spacers, such as stainless steel wool.

Abstract: The present invention relates to excimer laser equipment which is one kind of gas laser, and in particular to a rare gas-halide excimer laser using rare gases and halogens as laser media, and adapted to control the concentration of halogens contained in laser media therewithin on the basis of the result of the measurement of the concentration of halogens in the laser media which is being used for the oscillation of laser rays therein, whereby the stabilized oscillation of the laser is always possible.

Abstract: In order of maintaining at the more constant level the CO.sub.2 content in the gaseous mixture discharge of a transversely excited atmospheric pressure laser, a polymer product is included in advance of the laser operation in the laser chamber or within the closed fluidtight circuit where the gaseous mixture is recycled. Such polymer is produced by irradiating tripropylamine with ultraviolet photons and/or with energy electrons in the form of a layer whereby at least a portion of a solid support is coated.

Abstract: A method for injection locking a xenon chloride laser at 308.4 nm. Neon (Ne) is used as a diluent in the laser to shift slightly the gain profile of the laser towards the longer wavelengths and towards 308.4 nm. The laser is operated at a lower level of gain than is used in the prior art by using a lower level of electrical discharge than was used in the prior art. The lowered gain reduces the numerical magnitude of the difference in the gain of the laser at 308.4 nm and its gain at the highest gain modes of operation. Either a low level signal at 308.4 nm is injected into the laser to mode lock the lowered gain laser at 308.4 nm. or a frequency selection device such as etalons is inserted within the laser cavity to restrict operation to 308.4 nm. The period of the electrical discharge also is lengthened from that typically used in the prior art so as to obtain saturation of the output at 308.4 nm.

Abstract: For an excimer laser system utilizing in a laser chamber a lasing material and a mixture of a diluent rare gas and a heavy rare gas and halogen rare gas in given percentages there is disclosed a method and apparatus for reducing the expenditure of the rare gases by continuously evacuating the laser mixture from the laser chamber removing from the evacuated laser mixture any foreign halogen compounds to provide a cleaned laser mixture and thereafter feeding the cleaned lasing mixture back into the laser chamber. Along with the cleaned laser mixture there is fed in a supplementing lasing material which is a mixture of the halogen gas, the diluent gas and the heavy rare gas. The percentage of the halogen gas in the supplemental material is substantially greater than the given percentage in the lasing chamber while the percentages of the diluent gas and the heavy rare gas are substantially the same as the percentage ratios of the given percentages.

Abstract: A method of reducing an expenditure of a rare gas in an excimer laser system includes evacuating a lasing material including a mixture of diluent rare gas and removing therefrom halogen compounds. Supplemental lasing material is then added to the lasing mixture.

Abstract: The power output of a gas laser is maximized by (1) suppressing high order transverse modes, (2) broadening the gain curve to increase the number of axial modes that can lase in a given length of cavity and to thereby reduce power variation due to longitudinal mode sweeping resulting from thermal effects on cavity length, (3) suppressing unwanted infrared lasing activity, and (4) reducing beating noise resulting from frequency offset due to dispersion.

Abstract: An improved electric discharge XeF excimer laser employs a reaction gas mixture containing NF.sub.3 and F.sub.2 in proportions that tailor the kinetics of the electrochemical reactions in order to achieve a substantial increase in power.

Abstract: In electrically pumped CO.sub.2 gas lasers, there take place widely different chemical and physical processes which lead, at least partially, to undesirable interactions of the gases among themselves, and/or of the gases with the electrical and/or the optical field and/or with the materials used in the gas-filled chambers. Bodies that are equipped with surface area-enlarging structures are included in the discharge or resonator chamber or in adjacent secondary chambers. The secondary chambers by themselves act as reservoirs or as carriers of reservoirs for suitable catalysts and gas components and/or the heating of the catalysts, and have a predetermined influence over the conditions of volume and/or pressure and/or temperature. The inclusion of such secondary chambers and such structures which enlarge surface area inside the chambers make possible the attainment of at least an approximate state of equilibrium, which leads to uniformly good discharge and long life with high laser efficiency.

Abstract: A xenon fluoride (C.fwdarw.A) laser operating in the visible region is improved by the use of a synthesized buffer gas containing at least two components that combine to provide kinetic properties that are different from those of any single-component buffer gas.

Abstract: An improved method and apparatus for producing high power, high efficiency pulsed TEA laser energy at N.sub.2 O wavelengths by suppressing discharge arc formation with H.sub.2 or CO that is added to the N.sub.2 O lasing medium. Energy loading levels up to in the range of 266 J/L atm are achieved with gas mixtures of N.sub.2 lasing mediums and H.sub.2 or CO additives comprising N.sub.2 O:He:N.sub.2 :H.sub.2 ::0.03:0.69:0.27:0.01 and N.sub.2 O:He:N.sub.2 :CO::0.03:0.66:0.26:0.05 mole fraction.

Abstract: Visible and ultraviolet lasers is based on excimer transitions in the diatomic homonuclear halogen molecules. Electron beam pumping of argon and hydrogen iodide gas mixtures produces a strong green emission in I.sub.2 centered at 505 nm and a full width of half maximum (FWHM) of the gain spectrum of approximately 15 nm. The transition for the green I.sub.2 band is bound-to-free, so a laser on this transition is continuously tunable. The result is a room temperature excimer laser that is potentially tunable over a region of 150 .ANG. in the blue-green.

Abstract: An electric discharge gas laser utilizing a seedant material which is cooled prior to the main laser discharge. The seedant is ionized prior to the cooling process and prior to the main discharge, this pre-ionization maintaining the seedant material in a gaseous state even in view of the lowered temperature for a sufficient time so as to give the required ionization levels.

Abstract: A high power, electrically excited laser is disclosed wherein a laser gas is caused to flow through an excitation region in which an electric discharge is established along a direction transverse to the direction of flow of the laser gas between an anode and a porous cathode disposed on opposite sides of the excitation region, and wherein an electron beam is introduced into the excitation region along a direction parallel to the direction of the discharge. A first quantity of an auxiliary gas (preferably helium) having a normal glow current density at least an order of magnitude less than that of the laser gas is introduced into the upstream end of the excitation region adjacent to the cathode and caused to flow across the cathode surface along a direction parallel to that of the laser gas. A second quantity of the auxiliary gas is "bled" through the porous cathode and gradually added to the auxiliary gas stream flowing across the cathode surface.

Abstract: A combustion driven laser employs HBr as one of a plurality of lasing species. One embodiment of the invention lases simultaneously on the three species HF, HCl, HBr.

Abstract: The effective lasing lifetime of laser dyes including coumarin dyes are significantly extended by the use of an inert cover gas for the laser dye solution such as argon in combination with the employment of a glass filter such as Pyrex disposed between the pumping flash lamp and the dye laser cavity capable of absorbing electromagnetic radiation of about 300 nanometers or shorter wavelength.

Abstract: A laser cavity 15 is continuously flown through by a gas such as metastable iodine and other reactants, but continuous wave lasing is inhibited, except for brief periods to obtain pulsating emission of radiation; the optical energy content of the gas in the cavity 15 is, thus, depleted, and fresh gas flows into the cavity 15 during the pause following each pulse.

Abstract: In a gas laser in which a mixture of gases is excited under the influence of an electric field, a first constituent gas of the mixture is introduced into a laser tube to allow a discharge to occur in the introduced gas at predetermined partial pressure. A second constituent gas of the mixture is then introduced into the laser tube until the combined gases reach the normally operating pressure of the mixture to allow a discharge to occur in the later introduced gas.

Abstract: In a gasdynamic laser in which the hot flowing lasing medium (e.g. CO.sub.2 --N.sub.2) is cooled by expansion in a Laval nozzle 1, liquid droplets are introduced into the expanding lasing medium to increase the cooling effect. The liquid can be water, preferably heavy water, from a container 4 pressurized by the laser medium in plenum 6 and introduced from pipes 3 into a region immediately before the nozzle neck 2 so as to be atomized and accelerated through the neck 2. Evaporation occurs downstream of the neck and causes an increase in the cooling. The droplets preferably have a size in the range 1-20 .mu.m and may contain dissolved CO.sub.2. The droplets may be dispersed in a super cooled gas which is then injected into the lasing medium.

Abstract: A gasdynamic CO.sub.2 -laser in which the lasing medium is being cooled by expansion in a Laval nozzle, is operated in a way to amplify the cooling effect. This increased cooling is accomplished by introducing liquid droplets into the expanding lasing medium. These droplets are entrained by the flowing medium whereby the droplets are taken along with a speed corresponding approximately to the speed of the expanding lasing medium. The amplification of the cooling is accomplished by the evaporation of these droplets.

Abstract: The output power and efficiency of a gas discharge laser is substantially improved by the substitution of neon (Ne) for helium (He) as a buffer in the lasing medium. One embodiment of the invention is a pulsed excimer laser having a lasing gas comprising a mixture of krypton (Kr) and fluorine (F.sub.2). Use of Ne with the KrF excimer lasing medium further enables advantageous utilization of corona wire pre-ionization to initiate the main discharge of this type of laser.

Abstract: A method and apparatus for convection control of metallic halide vapor density in a metallic halide laser (10). More particularly, an apparatus is disclosed wherein a reservoir (48) containing copper chloride (62), which in the exemplary embodiment is the metallic halide chosen, is heated so that the copper chloride is maintained in a liquid form. The apparatus includes a means for flowing a buffer gas, which in the exemplary embodiment is neon, over the liquid copper chloride to provide a mixture of copper chloride vapor and neon (72') above the liquid copper chloride. A conduit (50) for providing fluid communication between the reservoir (68) containing the copper chloride vapor/neon mixture and the laser (10) is also included. The copper chloride vapor density in the laser is related to the liquid copper chloride temperature and the neon flow rate through the reservoir (68).

Abstract: A rare-gas hydrogen-halide laser is improved by including or adding a predetermined quantity of a hydrogen donor additive to its gas mixture. The closed-off operation lifetime of lasers such as XeCl, KrCl, or XeBr are tripled by adding up to 0.05% hydrogen to the laser gas mixture.

Abstract: A multi-line NH.sub.3 laser is disclosed pumped by a multi-longitudinal mode and multi-transverse mode laser beam from a high-pressure CO.sub.2 laser operating on the R(30) 9.2 .mu.m transition. The resulting comb of pumping wavelengths simultaneously pumps several close-lying sR(5,K) transitions in ammonia from the symmetric ground state to the antisymmetric .nu..sub.2 =1 state, providing simultaneous lasing on a plurality of sP(7,K) transitions of different K-values. A plurality of sP(5,K) ammonia laser lines originating in the .nu..sub.2 =1 antisymmetric band and terminating in the depleted lower pump levels are also generated.

Abstract: A method and apparatus is described for reducing the gas consumption rate by controlling the gas composition in a repetitively pulsed high pressure and/or high energy density TE CO.sub.2 laser. Detrimental gas species formed in the discharge are removed by chemical reaction in the gas phase and the reaction products are removed by a trap in a recirculator loop. In particular, the primary detrimental species is oxygen, the reducing gas added to remove this is hydrogen or deuterium and the resulting oxides of hydrogen or deuterium are removed by a molecular sieve.