Abstract: In a master oscillator plus power amplifier (MOPA) system, the oscillator is a passively Q-switched laser. The laser is triggered into passively Q-switched operation by operating an optical switch to resonantly couple back into the laser amplified stimulated emission generated by the amplifier.

Abstract: A microcrystal laser assembly including a gain-crystal includes a frame having a high thermal conductivity. The frame has a base with two spaced apart portions extending from the base. The gain-crystal has a resonator output minor on one surface thereof. The gain-crystal is supported on the spaced-apart portions of the frame in the space therebetween. Another resonator minor is supported in that space, spaced apart from the output mirror, on a pedestal attached to the base of the frame. The pedestal and the frame have different CTE. Varying the frame temperature varies the spacing between the resonator minors depending on the CTE difference between the pedestal and the frame.

Abstract: Apparatus for homogenizing and projecting two laser-beams is arranged such that the projected homogenized beams are aligned parallel to each other in a first transverse axis and partially overlap in second transverse axis perpendicular to the first transverse axis. The projected homogenized laser-beams have different intensities in the second axis and the degree of partial overlap is selected such that the combined intensity of the laser beams in the second axis has a step profile.

Abstract: A master oscillator power amplifier (MOPA) system includes an oscillator having a neodymium-doped gadolinium vanadate gain-medium and delivering seed-pulses. A length of single mode fiber is used to broaden the spectrum of the seed pulse. An amplifier having a neodymium-doped yttrium vanadate gain-medium amplifies the spectrally broadened seed-pulses. The gain-spectrum of the amplifier partially overlaps the broadened pulse-spectrum, providing spectral selection of the seed-pulses in addition to amplification. This provides amplified output-pulses having a duration about one-third that of the corresponding seed-pulses.

Abstract: A master oscillator power amplifier (MOPA) system includes an oscillator having a neodymium-doped gadolinium vanadate gain-medium and delivering seed-pulses. A length of single mode fiber is used to broaden the spectrum of the seed pulse. An amplifier having a neodymium-doped yttrium vanadate gain-medium amplifies the spectrally broadened seed-pulses. The gain-spectrum of the amplifier partially overlaps the broadened pulse-spectrum, providing spectral selection of the seed-pulses in addition to amplification. This provides amplified output-pulses having a duration about one-third that of the corresponding seed-pulses.

Abstract: A frequency-doubled OPS-laser having a desired output wavelength of 532 nm is tunable about that wavelength by a temperature tuned birefringent filter (BRF). The temperature of the BRF is varied while measuring transmission of a sample of the output through a Nd:YAG crystal having an absorption peak at a wavelength of about 532.4 nm. The peak is detected as a minimum of transmission and the temperature at which that minimum occurs is recorded. From wavelength-change-versus-temperature data for the BRF a temperature is calculated at which the output wavelength has the desired value and is maintained at that value to stabilize the output wavelength.

Abstract: A microcrystal laser assembly including a gain-crystal includes a frame having a high thermal conductivity. The frame has a base with two spaced apart portions extending from the base. The gain-crystal has a resonator output minor on one surface thereof. The gain-crystal is supported on the spaced-apart portions of the frame in the space therebetween. Another resonator minor is supported in that space, spaced apart from the output mirror, on a pedestal attached to the base of the frame. The pedestal and the frame have different CTE. Varying the frame temperature varies the spacing between the resonator minors depending on the CTE difference between the pedestal and the frame.

Abstract: A frequency-doubled OPS-laser having a desired output wavelength of 532 nm is tunable about that wavelength by a temperature tuned birefringent filter (BRF). The temperature of the BRF is varied while measuring transmission of a sample of the output through a Nd:YAG crystal having an absorption peak at a wavelength of about 532.4 nm. The peak is detected as a minimum of transmission and the temperature at which that minimum occurs is recorded. From wavelength-change-versus-temperature data for the BRF a temperature is calculated at which the output wavelength has the desired value and is maintained at that value to stabilize the output wavelength.

Abstract: Apparatus for homogenizing and projecting two laser-beams is arranged such that the projected homogenized beams are aligned parallel to each other in a first transverse axis and partially overlap in second transverse axis perpendicular to the first transverse axis. The projected homogenized laser-beams have different intensities in the second axis and the degree of partial overlap is selected such that the combined intensity of the laser beams in the second axis has a step profile.

Abstract: In a shifting algorithm for an optically nonlinear crystal arranged to frequency-convert beam of radiation, the location of one or more defects in the crystal is recorded as an exclusion zone. The location of the beam is stepped incrementally over a surface around a closed or open loop path in increments less than a beam dimension. The path is arranged such that the beam does not enter the exclusion zone.

Abstract: Two excimer lasers have individual pulsing circuits each including a storage capacitor which is charged and then discharged through a pulse transformer to generate an electrical pulse, which is delivered to the laser to generate a light pulse. The time between generation of the electrical pulse and creation of the light pulse is dependent on the charged voltage of the capacitor. The capacitors are charged while disconnected from each other. The generation of the electrical pulses is synchronized by connecting the capacitors together for a brief period after the capacitors are charged to equalize the charging voltages. The capacitors are disconnected from each other before they are discharged.

Abstract: An excimer laser includes a laser housing containing a lasing-gas mixture including a halogen. Contaminants including particulate matter and a metal halide vapor are generated in the lasing-gas mixture during operation of the laser. A gas-cleaning arrangement extracts lasing-gas mixture from the housing and passes the lasing-gas mixture through an electrode assembly. A repeatedly pulsed gas discharge is created in the electrode assembly by driving the electrode assembly with repeated high-power short-duration pulses. The pulsed discharge causes disintegration of the metal halide vapor and electrostatic trapping in the electrode assembly of the particulate matter and products of the metal halide disintegration.

Abstract: A method of operating a digitally modulated solid state laser is disclosed. The laser is optically pumped by a current-supply driven diode-laser radiation and with output-power stabilized at a desired value by a light regulator cooperative with a power monitor and the current source is disclosed. When the laser is turned on, the current-source is enabled and the light-regulator is disabled. A current regulator allows current from the current-supply to increase until the monitored power reaches the desired value. At this point, the light regulator is enabled and the light regulator assumes control of the current-supply for maintaining the output-power at the desired level.

Abstract: Two excimer lasers have individual pulsing circuits each including a storage capacitor which is charged and then discharged through a pulse transformer to generate an electrical pulse, which is delivered to the laser to generate a light pulse. The time between generation of the electrical pulse and creation of the light pulse is dependent on the charged voltage of the capacitor. The capacitors are charged while disconnected from each other. The generation of the electrical pulses is synchronized by connecting the capacitors together for a brief period after the capacitors are charged to equalize the charging voltages. The capacitors are disconnected from each other before they are discharged.

Abstract: In a silicon crystallization method, a pulse is delivered from each of two excimer lasers. The duration of one of the pulses is extended in a pulse-duration extender to a duration significantly longer than that of that of the other. The extended-duration and other pulses are delivered along a common path. The other pulse temporally overlaps the extended-duration pulse after delivery of the extended-duration pulse begins. The silicon is preheated by the extended-duration before being melted by the combined pulses during the temporal overlap period.

Abstract: Laser systems have a line-narrowed master oscillator and a power oscillator for amplifying the output of the master oscillator. The power oscillator includes optical arrangements for limiting the bandwidth of radiation that can be amplified. The limited amplification bandwidth of the power oscillator is relatively broad compared to that of the output of the master oscillator, but narrower than would be the case without the bandwidth limiting arrangements. The bandwidth narrowing arrangements of the power oscillator function primarily to restrict the bandwidth of amplified spontaneous emission generated by the power oscillator.

Abstract: Two excimer lasers have individual pulsing circuits each including a storage capacitor which is charged and then discharged through a pulse transformer to generate an electrical pulse, which is delivered to the laser to generate a light pulse. The time between generation of the electrical pulse and creation of the light pulse is dependent on the charged voltage of the capacitor. The capacitors are charged while disconnected from each other. The generation of the electrical pulses is synchronized by connecting the capacitors together for a brief period after the capacitors are charged to equalize the charging voltages. The capacitors are disconnected from each other before they are discharged.

Abstract: Arcing is minimized in a discharge chamber of a gas laser system by utilizing an electrode which comprises a surface portion capable of functioning as one of an anode and a cathode in order to energize a gas mixture in a discharge chamber of the gas discharge laser system, a shoulder portion being positioned on either side of the surface portion and being exposed to the gas mixture, and a coating layer made of electrically insulating material, wherein the coating layer is attached to the shoulder portion by a cold spraying method.

Abstract: A two-resonator laser arrangement for provides visible-wavelength radiation by sum-frequency mixing two different wavelengths of radiation circulating in the resonators in an optically nonlinear crystal located in the resonators. One of the resonators includes a solid-state gain-medium providing of one the two wavelengths and the other resonator includes a semiconductor gain-medium providing the other of the two wavelengths. A very short excited-state lifetime of the semiconductor gain-medium provides that noise and instability commonly encountered in the output of prior-art intra-resonator frequency-converted lasers is substantially reduced.

Abstract: Two excimer lasers have individual pulsing circuits each including a storage capacitor which is charged and then discharged through a pulse transformer to generate an electrical pulse, which is delivered to the laser to generate a light pulse. The time between generation of the electrical pulse and creation of the light pulse is dependent on the charged voltage of the capacitor. The capacitors are charged while disconnected from each other. The generation of the electrical pulses is synchronized by connecting the capacitors together for a brief period after the capacitors are charged to equalize the charging voltages. The capacitors are disconnected from each other before they are discharged.