Abstract: A laser frequency conversion system with ultraviolet-damage mitigation includes a nonlinear crystal for frequency converting a laser beam, and a one-dimensional beam expander arranged to receive the laser beam from the nonlinear crystal and expand a first transverse dimension of the laser beam. This expansion protects subsequent optical elements from ultraviolet damage. To mitigate ultraviolet damage to the nonlinear crystal and the beam expander, the system also includes one or more translation stages configured to translate the nonlinear crystal and the beam expander along a translation direction that is orthogonal to the first transverse dimension of the laser beam and non-parallel to a propagation direction of the laser beam through the nonlinear crystal and the beam expander.

Abstract: A mounting fixture for mounting an optical element on a base-plate has spaced-apart parallel legs attachable by brackets to the base-plate and a mounting platform attached to the legs. The platform can be heated by a removable heater. The optical element is held in a mounting tab attached to the platform by a solder-pad. Heating the platform softens the solder-pad allowing the tab and the element to be aligned. Removing the heat allows the pad to harden to complete the attachment and retain the alignment of the element on the mount.

Abstract: A fiber-MOPA includes a seed-pulse source followed by fiber amplifier stages. The seed pulse source delivers signal pulses for performing a laser operation and delivers radiation between the seed pulses to maintain the collective average of the seed pulse power and intermediate radiation power constant. Keeping this average power constant keeps the instantaneous available gain of the fiber amplifier stages constant. This provides that the seed pulse delivery can be changed from one regime to a next without a period of instability between the regimes.

Abstract: A mounting fixture for mounting an optical element on a base-plate has spaced-apart parallel legs attachable by brackets to the base-plate and a mounting platform attached to the legs. The platform can be heated by a removable heater. The optical element is held in a mounting tab attached to the platform by a solder-pad. Heating the platform softens the solder-pad allowing the tab and the element to be aligned. Removing the heat allows the pad to harden to complete the attachment and retain the alignment of the element on the mount.

Abstract: A fiber-MOPA includes a seed-pulse source followed by fiber amplifier stages. The seed pulse source delivers signal pulses for performing a laser operation and delivers radiation between the seed pulses to maintain the collective average of the seed pulse power and intermediate radiation power constant. Keeping this average power constant keeps the instantaneous available gain of the fiber amplifier stages constant. This provides that the seed pulse delivery can be changed from one regime to a next without a period of instability between the regimes.

Abstract: Frequency-multiplied fiber-MOPA apparatus includes one enclosure containing a master oscillator and fiber amplifier stages and another enclosure containing frequency-multiplying stages. Radiation is transmitted between the enclosures by a transport fiber in a flexible jacket or enclosure. The transport fiber functions additionally as a power amplifier fiber, and amplifies the radiation while transporting the radiation between the enclosures. The amplifying transport fiber is energized by diode-lasers in the enclosure containing the master oscillator and fiber amplifiers.

Abstract: A method for generating ultraviolet radiation includes sum-frequency mixing in one optically nonlinear crystal fundamental-wavelength radiation generated by a Pr:YLF gain-element with radiation having a second-harmonic wavelength of fundamental-wavelength radiation generated by a Pr:YLF gain-element. The second-harmonic wavelength is generated in another optically nonlinear crystal. The fundamental-wavelength radiation being mixed and the fundamental wavelength radiation from which the second-harmonic radiation is generated may have the same wavelength or different wavelengths.

Abstract: A frequency-conversion arrangement including one or more optically nonlinear crystals is located in an enclosure. Radiation residual from the frequency conversion is directed into an optical fiber having one end in the enclosure for receiving the residual radiation and an opposite end outside of the enclosure for disposing of the residual radiation outside of the enclosure.

Abstract: Laser apparatus including two different, pulsed MOPAs, one having a fundamental wavelength of 1064 nm and the other having a fundamental wavelength of 2114 nm, provide trains of optical pulses. The 1064-nm pulses are frequency-quintupled to a wavelength of 213 nm. The 2114-nm pulses are mixed with the 213-nm pulses to provide pulses having a wavelength of 193 nm. Each MOPA includes a fiber-laser and a bulk amplifier.

Abstract: Red light and green light are generated by passing portions of a beam of plane-polarized blue light through two resonators each including a praseodymium-doped gain-medium. One of the resonators generates green light and the other resonator generates red light in response to absorption of the blue light by the gain-medium. The amount of green or red light generated can be varied by varying the orientation of the polarization-plane of the blue light with respect to the gain-medium. The red light, green light, and a portion of the blue light not absorbed by the gain-media can be combined to form a beam of white light, or a beam of light of a predetermined color.

Abstract: Red light and green light are generated by passing a beam of plane-polarized blue light sequentially through two resonators each including a praseodymium-doped gain medium. A portion of the blue light is absorbed in the gain media and optically pumps the gain-media. Green light is generated in the first resonator and red light is generated in the second resonator. Green light from the first resonator is transmitted through the second resonator. Red light, green light, and unabsorbed blue light are delivered from the second resonator. Relative proportions of red light, green light, and blue light delivered from the second resonator can be varied by varying the orientation of the polarization-plane of the blue light with respect to the gain media. Sources of plane polarized blue light include optically pumped, frequency-doubled edge-emitting and surface-emitting semiconductor lasers.

Abstract: A laser-resonator includes a praseodymium-doped crystal gain-medium optically pumped by plane-polarized blue light delivered by a frequency-doubled, external cavity, surface-emitting semiconductor laser. The laser-resonator generates fundamental radiation at one of several possible wavelengths between about 500 nm and 750 nm. The fundamental wavelength generated is determined by a wavelength-selective element located in the laser-resonator and the polarization-orientation of the blue light relative to the c-axis of the crystal gain medium. An optically nonlinear crystal located in the laser-resonator frequency doubles the fundamental radiation to provide ultraviolet radiation.

Abstract: A diode pumped fiber laser is described that utilizes highly erbium-doped fluoride glass to produce 1 W and higher outputs at about 3 &mgr;m. High dopant concentrations in fluoride glass make it possible to efficiently pump the laser around 975 nm which in turn leads to higher slope efficiencies for the laser. Furthermore, by using this pumping wavelength, saturation of laser output due to bleaching of the ground state is overcome. The fluoride glass composition is a modified version of the standard ZBLAN composition. This altered composition achieves high glass quality, enables fiber drawing, and avoids the problem of crystallization.