Abstract: A laser system includes a seed source optically coupled to an extra cavity harmonic generator system may produce a round, non-astigmatic third harmonic output beam from a nominally round, non-astigmatic, diffraction limited input fundamental beam from the seed source. The system may include a second harmonic generation crystal. An input fundamental beam size is expanded in a non-walkoff direction for the SHG crystal at the SHG crystal input face. A higher harmonic generation crystal has an output face oriented at an oblique angle of incidence in a non-walkoff direction for the HHG crystal such that an output higher harmonic beam size is contracted in this direction. Expansion of the input fundamental beam at the SHG crystal input face exceeds reduction of third harmonic beam at the HHG crystal output face.

Abstract: An extra cavity harmonic generator system may produce a round, non-astigmatic third harmonic output beam from a nominally round, non-astigmatic, diffraction limited input fundamental beam. The system may include a second harmonic generation crystal. An input fundamental beam size is expanded in a non-walkoff direction for the SHG crystal at the SHG crystal input face. A higher harmonic generation crystal has an output face oriented at an oblique angle of incidence in a non-walkoff direction for the HHG crystal such that an output higher harmonic beam size is contracted in this direction. Expansion of the input fundamental beam at the SHG crystal input face exceeds reduction of third harmonic beam at the HHG crystal output face.

Abstract: A laser system includes a seed source optically coupled to an extra cavity harmonic generator system may produce a round, non-astigmatic third harmonic output beam from a nominally round, non-astigmatic, diffraction limited input fundamental beam from the seed source. The system may include a second harmonic generation crystal. An input fundamental beam size is expanded in a non-walkoff direction for the SHG crystal at the SHG crystal input face. A higher harmonic generation crystal has an output face oriented at an oblique angle of incidence in a non-walkoff direction for the HHG crystal such that an output higher harmonic beam size is contracted in this direction. Expansion of the input fundamental beam at the SHG crystal input face exceeds reduction of third harmonic beam at the HHG crystal output face.

Abstract: An extra cavity harmonic generator system may produce a round, non-astigmatic third harmonic output beam from a nominally round, non-astigmatic, diffraction limited input fundamental beam. The system may include a second harmonic generation crystal. An input fundamental beam size is expanded in a non-walkoff direction for the SHG crystal at the SHG crystal input face. A higher harmonic generation crystal has an output face oriented at an oblique angle of incidence in a non-walkoff direction for the HHG crystal such that an output higher harmonic beam size is contracted in this direction. Expansion of the input fundamental beam at the SHG crystal input face exceeds reduction of third harmonic beam at the HHG crystal output face.

Abstract: A universal fiber optic connector includes a housing and a fiber attachment element configured to attach an optical fiber in the housing. The attachment element positions the optical fiber such that an end face of the fiber is held within the housing. The fiber end face is positioned such that a beam of light emerging from the fiber end face has a defined wavefront located at a specified interface.

Abstract: A universal fiber optic connector includes a housing and a fiber attachment element configured to attach an optical fiber in the housing. The attachment element positions the optical fiber such that an end face of the fiber is held within the housing. The fiber end face is positioned such that a beam of light emerging from the fiber end face has a defined wavefront located at a specified interface.

Abstract: A universal fiber optic connector includes a housing and a fiber attachment element configured to attach an optical fiber in the housing. The attachment element positions the optical fiber such that an end face of the fiber is held within the housing. The fiber end face is positioned such that a beam of light emerging from the fiber end face has a defined wavefront located at a specified interface.

Abstract: A pulsed laser system may include a Raman fiber that is configured to act as multiple wavelength Raman laser. The fiber is configured to receive a pulsed input beam from an input source and convert the input beam to an output beam having narrow band outputs at first and second frequencies v1 and v2.

Abstract: A universal fiber optic connector includes a housing and a fiber attachment element configured to attach an optical fiber in the housing. The attachment element positions the optical fiber such that an end face of the fiber is held within the housing. The fiber end face is positioned such that a beam of light emerging from the fiber end face has a defined wavefront located at a specified interface.

Abstract: A pulsed laser system may include a Raman fiber that is configured to act as multiple wavelength Raman laser. The fiber is configured to receive a pulsed input beam from an input source and convert the input beam to an output beam having narrow band outputs at first and second frequencies v1 and v2.

Abstract: A pulsed laser system may include a Raman fiber that is configured to act as multiple wavelength Raman laser. The fiber is configured to receive a pulsed input beam from an input source and convert the input beam to an output beam having narrow band outputs at first and second frequencies v1 and v2.

Abstract: A nonlinear optical system may include optics, a non-linear optical crystal, and a uni-axial focusing element. The non-linear optical crystal is configured to generate an output beam from a non-linear optical interaction with an input beam. The optics are configured to image the input beam to an original input beam waist within the non-linear optical crystal, whereby the output beam has an original output beam waist. The uni-axial focusing element is optically coupled to the non-linear optical crystal. The uni-axial focusing element is configured so that the output beam has a new output beam waist at approximately the same location as the original output beam waist.

Abstract: A pulsed laser system may include a Raman fiber that is configured to act as multiple wavelength Raman laser. The fiber is configured to receive a pulsed input beam from an input source and convert the input beam to an output beam having narrow band outputs at first and second frequencies v1 and v2.

Abstract: Methods and systems for increasing the threshold for stimulated Brillouin scattering are described. A seed source may generate one or more chirped seed pulses characterized by a pulse duration ?, and a frequency chirp. The pulse duration ? may be greater than about 2 nanoseconds. A photonic crystal amplifier amplifies the seed pulses to produce one or more amplified pulses characterized by a peak power P greater than about 1 kilowatt. The pulse duration ?, frequency chirp, and the photonic crystal fiber may be selected such that a threshold for stimulated Brillouin scattering (SBS) in the photonic crystal fiber is greater than the peak power P.

Abstract: Control of average wavelength-converted power and/or wavelength converted pulse energy is described. One or more seed pulses may be generated and amplified with an optical amplifier to produce one or more amplified pulses. The amplified pulses may be wavelength converted to produce one or more wavelength converted pulses characterized by an average wavelength-converted power or pulse energy. Wavelength-converted power or pulse energy may be controlled by adjusting wavelength conversion efficiency without substantially changing the amplified power or pulse energy. Average wavelength-converted power may be controlled over a time scale comparable to a pulse period of the amplified pulses without adjusting an average power of the amplified pulses over the time scale comparable to a pulse period of the amplified pulses.

Abstract: Methods and systems for increasing the threshold for stimulated Brillouin scattering are described. A seed source may generate one or more chirped seed pulses characterized by a pulse duration ?, and a frequency chirp. The pulse duration ? may be greater than about 2 nanoseconds. A photonic crystal amplifier amplifies the seed pulses to produce one or more amplified pulses characterized by a peak power P greater than about 1 kilowatt. The pulse duration ?, frequency chirp, and the photonic crystal fiber may be selected such that a threshold for stimulated Brillouin scattering (SBS) in the photonic crystal fiber is greater than the peak power P.

Abstract: Control of average wavelength-converted power and/or wavelength converted pulse energy is described. One or more seed pulses may be generated and amplified with an optical amplifier to produce one or more amplified pulses. The amplified pulses may be wavelength converted to produce one or more wavelength converted pulses characterized by an average wavelength-converted power or pulse energy. Wavelength-converted power or pulse energy may be controlled by adjusting wavelength conversion efficiency without substantially changing the amplified power or pulse energy. Average wavelength-converted power may be controlled over a time scale comparable to a pulse period of the amplified pulses without adjusting an average power of the amplified pulses over the time scale comparable to a pulse period of the amplified pulses.

Abstract: A laser apparatus is disclosed. The apparatus includes a Neodymium-doped lasing material having first and second surfaces and a passive Q-switch optically coupled to the second surface. The first-surface is substantially transparent to a pump radiation and substantially reflective to laser radiation generated by an interaction between the pump radiation and the Neodymium-doped lasing material. The laser radiation is characterized by a vacuum wavelength corresponding to an atomic transition from the 4F3/2 level to the 4I9/2 level of Neodymium in the lasing material. The second surface transmits at least a portion of the laser radiation. The lasing material and Q-switch are configured to produce pulses of the laser radiation characterized by a pulse length of greater than zero and less than about 1.5 nanoseconds and a pulse repetition rate greater than about 100 kHz. A PQSL laser, an apparatus for generating blue light and a display system based on the laser apparatus are also disclosed.

Abstract: A light source is disclosed having a pulsed laser, a fiber amplifier optically coupled to the pulsed laser, and a nonlinear frequency converting element optically coupled to the fiber amplifier. The pulsed laser, e.g., a passively Q-switched laser, is configured to generate light pulses characterized by a pulse length of less than about 1.7 nsec and sufficiently large that a frequency bandwidth of the pulses after they emerge from the fiber amplifier is less than an acceptance bandwidth of the nonlinear frequency converting element. The laser is pulsed at a pulse repetition rate sufficiently large that the fiber amplifier does not spontaneously emit radiation between pulses. In such a source, the fiber amplifier is substantially free of stimulated Brillouin scattering and self-phase modulation may be held to a level that does not reduce conversion of infrared radiation to visible radiation. Such a light source can be combined with an image generator and a scanner in an image projection system.

Abstract: A method of producing a short-pass fiber by drawing a preform for a depressed cladding fiber at a predetermined drawing ratio. The preform has a core of refractive index n0, a depressed cladding surrounding the core and having a refractive index n1, and a secondary cladding surrounding the depressed cladding and having a refractive index n2. The core has a core cross-section and the depressed cladding has a depressed cladding cross-section that is larger than the core cross-section. The drawing ratio is determined based on the parameters of the preform measured along the axis of the preform and based on a desired minimum fundamental mode cutoff wavelength ?m. The final core cross-section defines a fundamental mode cutoff wavelength ?c such that ?c??m along the axis. Then the preform is pulled by the thus-determined drawing ratio to produce the short-pass fiber. In some embodiments a test section of the fiber is pulled first before pulling the short pass fiber.