Abstract: A self-adjusting interferometric outcoupler. In the most general sense, the invention is an optical system (100) comprising a first mechanism (112) for generating a first beam, a second mechanism (122) for receiving the first beam and returning a second beam, and an interferometer (116) positioned to couple the first beam to the second mechanism (122) and to receive and output the second beam, wherein the interferometer (116) is also shared by the first mechanism (112) and/or the second mechanism (122) to control the frequency of the first beam and/or the second beam, respectively. In the illustrative embodiment, the first mechanism (112) is a master oscillator, the second mechanism (122) is a phase conjugate mirror, and the system (100) further includes a power amplifier (118) positioned to amplify the first beam during a first pass and to amplify the second beam during a second pass.

Abstract: A system for removing waste energy in the form of sensible heat and fluorescent energy from a solid state laser medium having a broad surface. The system includes a manifold disposed about the laser medium having a plurality of inlet jets interspersed with a plurality of exhaust orifices. Coolant fluid is circulated through the manifold. The fluid is forced through the plurality of inlet jets to impinge the broad face of the laser medium, thereby transferring waste energy by convection from the laser medium to the coolant fluid. The coolant fluid is further circulated to exhaust the pumphead manifold through the plurality of exhaust orifices. The fluorescent energy, which is radiated from the laser medium, is converted to sensible heat by an absorber disposed within the coolant adjacent to the laser medium. The coolant then removes the converted heat by forced convection.

Abstract: A laser cooling apparatus and method. Generally, the inventive apparatus includes a mechanism for transporting sensible thermal energy from a solid state laser and for communicating waste fluorescent radiation therefrom as well. In the illustrative embodiment, the apparatus includes an optically transparent manifold with an inlet port, an exhaust port and a plurality of spray nozzles therebetween adapted to direct a cooling fluid on the laser medium of a laser. In addition, the optically transparent manifold is used to permit waste fluorescent radiation to escape the confines of the laser and cooling system means such that said fluorescent radiation may be optically directed to an external heat sink such as free space.

Abstract: A laser cooling apparatus and method. Generally, the inventive apparatus includes a mechanism for transporting sensible thermal energy from a solid state laser and for communicating waste fluorescent radiation therefrom as well. In the illustrative embodiment, the apparatus includes an optically transparent manifold (10) with an inlet port (12), an exhaust port (19) and a plurality of spray nozzles (16) therebetween adapted to direct a cooling fluid on the laser medium (20) of a laser (30). In addition, the optically transparent manifold (10) is used to permit waste fluorescent radiation to escape the confines of the laser and cooling system means such that said fluorescent radiation may be optically directed to an external heat sink such as free space.

Abstract: A high gain optical amplifier and method. Generally, the inventive amplifier includes a first crystal having an axis and a first index of refraction and a second crystal bonded to the first crystal about the axis and having a second index of refraction. The first index is higher than the second index such that light through the first crystal is totally internally reflected. In the illustrative embodiment, the first crystal is Yb:YAG with an index of approximately 1.82, the second crystal is Sapphire with an index of approximately 1.78, and the axis is the propagation axis. The invention is, in its preferred embodiment, a light guide fabricated out of crystalline materials, diffusion bonded together. If the core of the light guide is doped with laser ions, high gain amplifiers made be designed and operable over a large étendue.

Abstract: A solid state waveguided structure a core fabricated of a lasing medium, diffusion-bonded to a cladding fabricated of a laser-inactive material. The medium of the core comprises a lutetium-aluminum-garnet material doped with ions of ytterbium, lutetium-aluminum-garnet material doped with ions of neodymium, and lutetium-aluminum-garnet material doped with ions of thulium, and the laser-inactive material of the cladding comprises an yttrium-aluminum-garnet material. A method of fabricating a solid state waveguided structure with improved characteristics comprising using a combination of a trivalent ions of ytterbium-doped lutetium-aluminum-garnet core and a yttrium-aluminum-garnet cladding.

Abstract: An optical system for producing high power laser beams has an in/out coupler for receiving an input laser beam from an oscillator. The coupler inputs the beam to a first multiplexer which produces a plurality of beams which are sent to a plurality of fiber amplifiers. A second beam multiplexer receives the thus amplified plurality of beams to combine then into a single amplified beam which is input to a loop PCM (phase conjugate mirror). A multi-mode fiber amplifier is included in the loop PCM. The output of the loop PCM is phase conjugated with the amplified beam input to the loop PCM thereby eliminating any phase and polarization distortions and aberrations occurring in the fiber amplifiers. The output of the loop PCM is supplied in reverse direction through the second multiplexer, the fiber amplifiers and the first multiplexer in that order and then through the in/out coupler as a high power output laser beam.

Abstract: A high gain optical amplifier and method. Generally, the inventive amplifier includes a first crystal having an axis and a first index of refraction and a second crystal bonded to the first crystal about the axis and having a second index of refraction. The first index is higher than the second index such that light through the first crystal is totally internally reflected. In the illustrative embodiment, the first crystal is Yb: YAG with an index of approximately 1.82, the second crystal is Sapphire with an index of approximately 1.78, and the axis is the propagation axis. The invention is, in its preferred embodiment, a light guide fabricated out of crystalline materials, diffusion bonded together. If the core of the light guide is doped with laser ions, high gain amplifiers made be designed and operable over a large étendue.

Abstract: A laser comprising a master oscillator and a loop phase conjugate mirror (Loop-PCM) for substantially eliminating transient relaxation oscillations to instead form controlled sustained pulsations. In a preferred embodiment suitable for material processing applications with high power requirements, the master oscillator is part of a Phase Conjugate Master Oscillator Power Amplifier (PC-MOPA). A method for processing a material using a Loop-PCM by determining and using an optimal pulse fluence, duration and spacing is provided. Using pulses of the kind which are produced by the transient, and normally not desirable, relaxation oscillations common to Nd:YAG and other lasers, relaxation oscillations with controllable pulse duration, repetition rate and duty cycle are generated, making it ideal for materials processing.

Abstract: A polarization insensitive optical attenuator is disclosed. Three birefringent wedges are disposed along an optical path with their respective optical axes aligned. The apex angle of the second wedge equals the sum the apex angles of the first and third wedges. A Faraday rotator is disposed along the optical path between the first and the second wedge. A reciprocal rotator is disposed along the optical path adjacent to the Faraday rotator. An optical signal transmitted through the attenuator may be selectively divided into three spatially separate output rays while maintaining a predetermined attenuation or substantially complete isolation from reflected signals. Adjustment of the optical rotation angles allows the attenuator to be easily adapted to a wide variety of industrial and commercial laser applications.

Abstract: A loop four-wave mixing phase conjugator that can be used with depolarized signal beams comprises a polarization separator, a polarization mixer, an optical diode, a gain medium and relay optics that together form a unidirectional laser resonator. In operation, the polarization separator separates a signal beam .epsilon..sub.1 into orthogonally polarized signal beam components .epsilon..sub.11 and .epsilon..sub.12 and directs them to a nonlinear medium. The components propagate through the nonlinear medium and emerge as loop beam .epsilon..sub.2, with orthogonally polarized components .epsilon..sub.2 and .epsilon..sub.22. The polarization mixer mixes the energy from the two orthogonally polarized loop beam components, and relay optics direct the loop beam components back to the nonlinear medium at an angle with respect to the input beam. The loop beam components intersect and optically interfere with signal beam components .epsilon..sub.11 and .epsilon..sub.22 in the nonlinear medium to form gratings.

Abstract: A compact loop four-wave mixing phase conjugator that can be used in practical optical applications comprises a reflective nonlinear cell, relay optics, an optical gain medium, and an optical diode that together form a unidirectional ring laser resonator. In operation, a signal beam .epsilon..sub.1 is directed to the nonlinear cell, where it passes through a nonlinear medium contained within the cell and is reflected out of the cell as loop beam .epsilon..sub.2. The relay optics direct loop beam .epsilon..sub.2 through the optical diode, optical gain medium, and back to the nonlinear cell, where it intersects and optically interferes with the signal beam .epsilon..sub.1 to form a refractive index grating in the nonlinear medium. The optical diode and gain medium are positioned in the loop so that an oscillation beam .epsilon..sub.3 builds up from optical noise in the resonator and oscillates in a direction counter to the propagation direction of loop beam .epsilon..sub.2. A portion of oscillation beam .