Litton Systems, Inc.

Northrop Grumman Systems Corporation

Martin Marietta Corporation

Ronald R Selleck

Steve Guch, Jr

Floyd E Hovis

Stephen E Davis

Bart A Shepherd

Walter R Sanders

Anna Tabirian

Douglas P Stanley

Phuoc Khanh Nguyen

Larry G Jones

Charles L Stonecypher

James M Martin

William S Brockett

Michael G Croteau

Lloyd H Morton

William L Moon

William M Roberts

Robert K Bratton

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 theIlevel to theIlevel of Holmium. The pump source produces pulses having a duration that is at least as long as a storage time of theIlevel of the laser medium. The pump source pumps the laser medium with signals having a wavelength shorter than 1.67 &#x3bc;m, with the laser medium producing an output having a wavelength of about 1.67 &#x3bc;m.

Method and apparatus for producing an eye-safe laser

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. Intracavity optical switching of the laser resonator is used to achieve the two distinct modes of operation, the first being conventional Q-switched operation with pulse width equivalent to several cavity round trip times and the second being Q-switched cavity, dumped operation with pulse width equivalent to about one cavity round trip time. Use of this apparatus with external frequency shifting optics is also described.

Multiple mode laser

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.

Q-switch laser method and apparatus

A laser apparatus includes a hollow cylindrical solid state laser medium and an optical resonator having reflective surfaces at each end of the laser medium in the axial direction of the laser medium for causing a light emitted into the laser medium to travel back and forth along the elongated axial direction of the laser medium. One of the reflective surfaces of the optical resonator is shaped to reflect the beam at an angle to the beam impinging thereagainst to thereby walk the beam tangentially around the hollow cylindrical solid state laser medium at a fixed radial distance from the elongated axis of the laser medium. An exit slot is formed in one of the reflective surfaces. A pumping means for exciting the laser medium includes at least one flashlamp positioned adjacent the laser medium along the laser medium axis through the hollow cylindrical portion of the laser.

Laser apparatus

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. The compact multiple resonator laser system has a substrate mirror system having four mirror surfaces thereon positioned to form two laser resonators. A multi-pass corner cube is mounted to fold the light beams between a pair of substrate mirrored surfaces while a transfer corner cube is positioned to transfer a laser beam from one resonator to the second resonator to form a very compact pair of laser resonators. One of the laser resonators is a dual resonator forming both the laser resonator and an optical parametric oscillator resonator.

Compact laser apparatus

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. The compact multiple resonator laser system has a substrate mirror system having four mirror surfaces thereon positioned to form two laser resonators. A multi-pass corner cube is mounted to fold the light beams between a pair of substrate mirrored surfaces while a transfer corner cube is positioned to transfer a laser beam from one resonator to the second resonator to form a very compact pair of laser resonators. One of the laser resonators is a dual resonator forming both the laser resonator and an optical parametric oscillator resonator. A method of producing a coherent light beam of a predetermined output wavelength uses the compact laser system apparatus.

Compact laser apparatus and method

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.

Fiber-optic rotation rate sensor having dual interferometer loops

Growing community of inventors

Winter Park, FL, United States of America

Ronald R Selleck