Abstract: A lasing apparatus includes a laser medium and a pump source. The laser medium includes one of a Holmium-doped fluoride crystal or a Holmium-doped fluorozirconate ZBLAN glass fiber. The pump source generates pulses that resonantly pump the laser medium such that the laser medium produces an output from the 5I5 level to the 5I7 level of Holmium. The pump source produces pulses having a duration that is at least as long as a storage time of the 5I5 level of the laser medium. The pump source pumps the laser medium with signals having a wavelength shorter than 1.67 ?m, with the laser medium producing an output having a wavelength of about 1.67 ?m.

Abstract: A laser apparatus is described having multiple modes of operation using intracavity optical switching within a laser resonator. The laser resonator has a solid state gain medium and one or more optical switches located between a pair of end reflectors. The pump for the gain medium has controlled duration to allow varying the pumping energy and pulse repetition rate. The laser has a Q-switched mode for generating energy from the laser resonator at a fixed level of outcoupling when the laser pump is operated to produce a range of predetermined pulse, rates and durations. The laser also has a cavity dumped mode of operation in which the laser pump is operated to produce a second range of predetermined higher pulse repetition rates and shorter pulse durations so that the pulse energy, rate and duration are selected by first Q-switching with essentially no outcoupling and then rapidly cavity dumping all the optical energy in the resonator.

Abstract: A Q-switch laser apparatus includes a laser cavity formed with a pair of reflective surfaces having a laser medium mounted therebetween and a power supply operatively connected to the laser cavity to pump the laser medium. An electro-optic Q-switch is mounted in the laser cavity in a saturable absorber of less than 100% saturable transmittance is located in the laser cavity between the laser medium and the electro-optic Q-switch for suppressing prelasing in the laser. The saturable absorber may be a Cr4+:YAG used with an electro-optic Q-switch of LiNbO.sub.3. The method includes selecting the laser apparatus and selecting a saturable absorber of less than 100% saturable transmittance and attaching the selected saturable absorber in the laser cavity between the laser medium and the electro-optic Q-switch for suppressing prelasing therein.

Abstract: A laser system includes an apparatus having a primary laser resonator having a laser medium therein for producing a laser beam of a first wavelength and a second laser resonator optically connected to the primary resonator to allow a portion of the laser energy from the primary laser resonator to pass into the secondary laser resonator. An optical parametric oscillator is located intracavity of the secondary laser resonator and includes a nonlinear crystal for producing a laser beam of a second wavelength therefrom. A coherent beam output is coupled to the optical parametric oscillator for producing an output beam of predetermined wavelength of the second wavelength while blocking the output of the laser beam of the first wavelength so that a dual resonator combines a secondary laser cavity and an optical parametric oscillator to produce a predetermined output wavelength.

Abstract: A laser system includes an apparatus and method having a primary laser resonator having a laser medium therein for producing a laser beam of a first wavelength and a second laser resonator optically connected to the primary resonator to allow a portion of the laser energy from the primary laser resonator to pass into the secondary laser resonator. An optical parametric oscillator is located intracavity of the secondary laser resonator and includes a non-linear crystal for producing a laser beam of a second wavelength therefrom. A coherent beam output is coupled to the optical parametric oscillator for producing an output beam of predetermined wavelength of the second wavelength while blocking the output of the laser beam of the first wavelength so that a dual resonator combines a secondary laser cavity and an optical parametric oscillator to produce a predetermined output wavelength.

Abstract: A fiber optic rotation rate sensor employs two fiber loop interferometers. Two Sagnac fiber optic interferometers are interleaved such that both fibers are contained in each each interferometer. A coherent light beam at one frequency is proprogated in only one of the fibers, and an opticl beam at another frequency is proprogated in the other fiber. The beam emerging from one of the fibers is combined with the beam emerging from the other of the fibers for each of the two ends of each fiber to produce a pair of interference signals each having a frequency equal to the difference between the two light beam frequencies. The relative phase of these two signals is then determined to provide an indication of the rate of angular rotation of the fiber optic loops, and this determination is independent of any temperature-related characteristics that produce offset phase errors.