Abstract: An electro-optical switch includes an optical assembly arranged to transmit laser-radiation. The optical assembly comprises an active optical crystal. On one of two opposite surfaces of the crystal is an optical window formed from a material having a refractive index lower than the material of the crystal. Heat deposited, as a result of transmission of the laser-radiation, at the surface of the crystal in contact with the widow is transferred to the window, thereby reducing the potential for optical damage to the crystal surface. The window is sufficiently thick that it has an odd integer multiple of quarter-wavelengths optical thickness at a wavelength about equal to a wavelength of the laser-radiation, thereby behaving as an antireflection device for the crystal at that wavelength. In one embodiment of the optical assembly, the active optical crystal is a cadmium telluride crystal and the window is formed from cesium bromide.

Abstract: A pulsed, Q-switched, waveguide CO2 laser includes a plurality of waveguide channels formed in a block of a beryllium oxide ceramic material and is operated at a wavelength between about 9.2 and 9.7 micrometers. The laser has an output power up to 55% greater than that of a similarly configured laser, operated at the same wavelength and pulse conditions, but wherein the waveguide channels are formed in a block of an alumina ceramic material.

Abstract: A laser includes a gain medium located in a laser resonator. The gain medium generates plane polarized radiation plane polarized in a first polarization orientation. An electro-optical switch is located in the resonator. When the switch is activated the polarization plane of the laser radiation is rotated to a second orientation after making a forward and a reverse pass through the optical switch. When the switch is deactivated, the polarization orientation of the forward and reverse transmitted laser radiation remains about the same. A polarization selective device is located in the resonator between the electro-optical switch and the gain medium. The polarization selective device is arranged to permit circulation in the resonator of laser radiation in the first polarization orientation, and to restrict circulation of laser radiation in the second polarization orientation. The Gain medium is energized and the switch activated to allow energy to build in the gain medium.

Abstract: The quality of pulses output from laser systems such as super-pulsed CO2 slab lasers can be improved using half-wavelength electro-optic modulators (EOMs), in combination with thin film polarizers (TFPs). A voltage applied across a CdTe crystal of the EOM rotates the polarization of a pulse passing through the EOM by 90°. The polarization determines whether the pulse passes through, or is redirected by, the TFP. The voltage applied to the crystal can be pulsed to prevent a drop in charge, which could allow radiation to leak to the application. A totem pole switch used to apply voltage to the EOM can receive a pulsed voltage for improved performance. Directing by the EOM allows pulses to be clipped at the front/back end(s), split into portions, and/or directed to separate scanners. Directing pulses or pulse portions to different scanners can increase the output of systems such as hole drilling systems.

Abstract: Multiple laser beams, each having a shape such as a Gaussian profile, can be incoherently combined to obtain a shaped, flat top laser beam. The combined laser beams can provide power levels necessary for material processing applications such as annealing, drilling, and cutting, while minimizing the amount of unused power. The lasers can be positioned in an array in order to shape the flat top beam, and can be staggered in position where necessary to give each output beam an equal beam path length. The relative frequencies and/or powers of the lasers can be adjusted to control the flatness and stability of the incoherently combined beam.

Abstract: A pulsed, Q-switched, waveguide CO2 laser includes a plurality of waveguide channels formed in a block of a beryllium oxide ceramic material and is operated at a wavelength between about 9.2 and 9.7 micrometers. The laser has an output power up to 55% greater than that of a similarly configured laser, operated at the same wavelength and pulse conditions, but wherein the waveguide channels are formed in a block of an alumina ceramic material.

Abstract: A simultaneously super pulsed Q-switched CO2 laser system for material processing comprises sealed-off folded waveguides with folded mirrors that are thin film coated to select the output wavelength of the laser. The system also comprises a plurality of reflective devices defining a cavity; a gain medium positioned within the cavity for generating a laser beam; a cavity loss modulator for modulating the laser beam, generating thereby one or more laser pulses; a pulsed signal generation system connected to the cavity loss modulator for delivering pulsed signals to the cavity loss modulator thereby controlling the state of optical loss within the cavity; a control unit connected to the pulsed signal generation system for controlling the pulsed signal generation system; and a pulse clipping circuit receptive of a portion of the laser beam and connected to the pulsed signal generation system for truncating a part of the laser pulses.

Abstract: A laser includes a gain medium located in a laser resonator. The gain medium generates plane polarized radiation plane polarized in a first polarization orientation. An electro-optical switch is located in the resonator. When the switch is activated the polarization plane of the laser radiation is rotated to a second orientation after making a forward and a reverse pass through the optical switch. When the switch is deactivated, the polarization orientation of the forward and reverse transmitted laser radiation remains about the same. A polarization selective device is located in the resonator between the electro-optical switch and the gain medium. The polarization selective device is arranged to permit circulation in the resonator of laser radiation in the first polarization orientation, and to restrict circulation of laser radiation in the second polarization orientation. The Gain medium is energized and the switch activated to allow energy to build in the gain medium.

Abstract: An electro-optical switch includes an optical assembly arranged to transmit laser-radiation. The optical assembly comprises an active optical crystal. On one of two opposite surfaces of the crystal is an optical window formed from a material having a refractive index lower than the material of the crystal. Heat deposited, as a result of transmission of the laser-radiation, at the surface of the crystal in contact with the widow is transferred to the window, thereby reducing the potential for optical damage to the crystal surface. The window is sufficiently thick that it has an odd integer multiple of quarter-wavelengths optical thickness at a wavelength about equal to a wavelength of the laser-radiation, thereby behaving as an antireflection device for the crystal at that wavelength. In one embodiment of the optical assembly, the active optical crystal is a cadmium telluride crystal and the window is formed from cesium bromide.

Abstract: An EOM Q-switched CO2 laser produces bursts of laser pulses delivered at a high PRF such as 20-140 kHz and having a short high-power spike of about 80-150 ns followed by a lower-power tail of about 0.05-12.0 &mgr;s. The bursts and/or laser pulses can be shaped by controlling the RF pumping duty cycle, the delay between the onset of RF pumping and the initiation of Q-switching, the pulse repetition frequency, and/or the duration of the tail. The bursts of laser pulses can be adapted to facilitate machining of metal layers and/or layers containing materials having disparate vaporization temperatures and/or disparate melting points, such as FR4 or green ceramics.