Abstract: An apparatus and method applicable for generating ultraviolet laser light having a wavelength in the 200-nm range and/or 250-nm range; in some embodiments, using a single fiber laser pump source (in some embodiments, a pulsed source). In some embodiments, the invention provides methods of generating 250-nm or 200-nm photons using a mode-locked 1000-nm fiber laser and efficient 4th/5th harmonic frequency up-conversion. In other embodiments, the invention uses continuous wave (cw) single-frequency fiber lasers and external resonant frequency conversion. In still other embodiments, the invention uses cw single-frequency optically-pumped semiconductor lasers (OPSLs) and electrically driven vertical-cavity surface-emitting lasers (VCSELs) and externally resonant frequency conversion.

Abstract: A wide variety of Fiber Bragg writing devices comprising solid state lasers are provided. The solid state lasers emit moderate peak-power output beams which are suitable for efficient production of fiber Bragg gratings without causing embrittlement of the optical waveguide. These solid state lasers generate fourth harmonic output beams with wavelengths of approximately 240 nm, in order to match the primary absorption peak in the ultraviolet range for a typical optical waveguide. Some of these solid state lasers comprise a fequency-doubling crystal and a CLBO crystal used in a non-critically phase-matched orientation as a frequency-quadrupling crystal. In such lasers, both the frequency-doubling crystal and frequency-quadrupling crystal are preferably engineered to minimize or eliminate beam “walkoff.

Abstract: Efficient devices and methods for producing ultraviolet light are provided. One such device includes a diode-pumped 946 nanometer solid state laser, a first nonlinear crystal for generating blue light at approximately 473 nanometers, and a second nonlinear crystal for doubling the frequency of the blue light to produce a fourth harmonic beam of ultraviolet light at approximately 236.5 nanometers. In some embodiments, the second nonlinear crystal is a cooled CLBO crystal angle-tuned for non-critical phase-matching to provide high conversion efficiency. Some embodiments include a second laser which emits a fundamental beam having a wavelength of more than one micron and a third nonlinear crystal for sum-frequency mixing the fundamental beam and the fourth harmonic beam to output an ultraviolet beam having a wavelength of less than 200 nanometers.

Abstract: Methods and devices are provided for converting a fundamental wavelength of a fundamental beam generated by a surface-emitting diode laser having a first resonating cavity. According to some embodiments, a first nonlinear crystal disposed in a second resonating cavity external to first resonating cavity converts the fundamental beam to a first output beam having a first output wavelength different from the fundamental wavelength. Some embodiments include a second nonlinear crystal, which may be disposed in the second resonating cavity or in a third resonating cavity, for producing a second output beam having a second output wavelength different from the first output wavelength. In some such embodiments, the second nonlinear crystal converts the wavelength of the first output beam to produce the second output beam. In some embodiments, the second nonlinear crystal interacts with the first output beam and an infrared beam from another laser device to produce the second output beam.

Abstract: A wide variety of Fiber Bragg writing devices comprising solid state lasers are provided. The solid state lasers emit moderate peak-power output beams which are suitable for efficient production of fiber Bragg gratings without causing embrittlement of the optical waveguide. These solid state lasers generate fourth harmonic output beams with wavelengths of approximately 240 nm, in order to match the primary absorption peak in the ultraviolet range for a typical optical waveguide. Some of these solid state lasers comprise a frequency-doubling crystal and a CLBO crystal used in a non-critically phase-matched orientation as a frequency-quadrupling crystal. In such lasers, both the frequency-doubling crystal and frequency-quadrupling crystal are preferably engineered to minimize or eliminate beam “walkoff.

Abstract: Efficient devices and methods for producing ultraviolet light are provided. One such device includes a diode-pumped 946 nanometer solid state laser, a first nonlinear crystal for generating blue light at approximately 473 nanometers, and a second nonlinear crystal for doubling the frequency of the blue light to produce a fourth harmonic beam of ultraviolet light at approximately 236.5 nanometers. In some embodiments, the second nonlinear crystal is a cooled CLBO crystal angle-tuned for non-critical phase-matching to provide high conversion efficiency. Some embodiments include a second laser which emits a fundamental beam having a wavelength of more than one micron and a third nonlinear crystal for sum-frequency mixing the fundamental beam and the fourth harmonic beam to output an ultraviolet beam having a wavelength of less than 200 nanometers.

Abstract: Methods and devices are provided for converting a fundamental wavelength of a fundamental beam generated by a surface-emitting diode laser having a first resonating cavity. According to some embodiments, a first nonlinear crystal disposed in a second resonating cavity external to first resonating cavity converts the fundamental beam to a first output beam having a first output wavelength different from the fundamental wavelength. Some embodiments include a second nonlinear crystal, which may be disposed in the second resonating cavity or in a third resonating cavity, for producing a second output beam having a second output wavelength different from the first output wavelength. In some such embodiments, the second nonlinear crystal converts the wavelength of the first output beam to produce the second output beam. In some embodiments, the second nonlinear crystal interacts with the first output beam and an infrared beam from another laser device to produce the second output beam.

Abstract: Apparatus and method for modulating the phase or the amplitude of a monochromatic light beam, the apparatus including in one embodiment a Mach-Zehnder interferometer that consists of two beam splitters or beam combiners, a fully reflective mirror and an electro-optical crystal for modulation of one of two beam components. The electro-optical crystal serves as an optical resonator for the portion of the light beam admitted into the crystal material, using total internal reflection of the light beam from two or more of the crystal surfaces. The crystal has a high finesse so that a relatively small change in voltage applied across the crystal produces a large (.apprxeq.180.degree.) change in the external phase shift associated with the modulated component of the light beam.

Abstract: A wavelength selective mirror provides single wavelength operation of a gas laser. In a specific embodiment an output coupler optical interference coating allows oscillation of the 488.0 nanometer line of the Argon ion laser blue/green spectrum while suppressing all other lines in that spectrum, particularly adjacent lines at 476.5 nanometers and 496.5 nanometers.