Abstract: In one of the embodiments, a dark channel array is provided which includes gain channels, each configured to emit an output beam from an output surface and to have a light wave propagating therethrough. It further includes a dark channel configured to emit an output beam from the output surface of the dark channel array and to have a light wave propagating in the dark channel, such that output beams from the plurality of gain channels are coherently coupled in phase with each other. The dark channel array is configured such that the dark channel captures a portion of the output beam from at least two of the plurality of gain channels by radiant coupling.

Abstract: A thin disk laser includes a thin disk of a host material incorporating a laser gain medium. The disk has opposite first and second surfaces, at least one of which is non-planar. The first surface is coated with a high reflectivity coating. The second surface has an anti-reflection coating thereon. The shape and mounting of the laser is such that mismatch of the coefficients of thermal expansion between the disk laser and the mount does not affect scaling of the laser to larger size disks for higher power lasers.

Abstract: The present invention comprises a method and apparatus to increase the efficiency of photovoltaic conversion of light into electrical power and to achieve operation at higher optical power and therefore higher electrical power. Preferred embodiments increase the efficiency of photovoltaic power conversion of any source of a beam of photons by spatially dividing the beams into a plurality of individual beamlets, each beamlet focusing on an active photovoltaic region. The preferred architecture of the apparatus of the invention comprises spatially separated photovoltaic cells to substantially match the pattern of the spatially separated plurality of beamlets. Preferred embodiments result in a significant reduction in ohmic losses and current shunting, thereby increasing photovoltaic conversion efficiencies.

Abstract: A laser apparatus having multiple laser devices coupled together. The laser devices comprise optical fibers with laser active regions. Each of the fibers has a reflector disposed at one end and is connected to a combiner on the other end. A laser pump device for each fiber provides pump energy to the laser active regions. Light propagating in the fibers interacts so as to form inphase states. The array of fibers may be coupled either in pairs or altogether between the reflector and the laser active region.

Abstract: In one embodiment, a dark channel array is provided which includes gain channels, each gain channel being configured to emit an output beam, and which includes a dark channel configured to cause output beams from the gain channels to be coherently couple in phase with each other.

Abstract: A thin disk laser includes a thin disk of a host material incorporating a laser gain medium. The disk has opposite first and second surfaces, at least one of which is non-planar. The first surface is coated with a high reflectivity coating. The second surface has an anti-reflection coating thereon.

Abstract: A fiber optic apparatus formed by fusing together multiple optical fibers and stretching the fused optical fibers to form a tapered portion. The tapered portion is cleaved or cut and polished to form a facet at which an optical beam is received or transmitted.

Abstract: A laser apparatus having multiple laser devices coupled together. The laser devices include optical fibers with laser active regions. Each of the fibers has a reflector disposed at one end and is connected to a combiner on the other end. A laser pump device for each fiber provides pump energy to the laser active regions. Light propagating in the fibers interacts so as to form inphase states. The array of fibers may be coupled either in pairs or altogether between the reflector and the laser active region.

Abstract: A solid state pump cavity comprising a laser rod encased by diffusion bonding inside an outer cladding. The outer cladding provides the ability to efficiently conduct heat away from the laser rod. The outer cladding is also configured to absorb spontaneous laser radiation that would otherwise be re-amplified by the laser rod. Diffusion bonding of the outer cladding to the laser rod forms a seamless optical boundary between the outer cladding and the laser rod. An alternative embodiment of the pump cavity comprises multiple segments of laser rod and outer cladding assemblies coupled together with undoped sections that are diffusion bonded to the ends of the laser rod and outer cladding assemblies.

Abstract: A multiple-fiber, stretched, fused and cleaved coupler designed to act as an output window to a fiber laser array or fiber-coupled laser array, in which the stretch, length and/or position of the fibers is chosen facilitate the in-phase oscillation of the lasers in the array. The in-phase oscillation of the lasers is facilitated by making one or more of the fibers interferometrically dark. The other fibers, the interferometrically lit ones, are made to have fairly uniform intensity under the same collimated illumination.

Abstract: A method and apparatus for compensating for phase fluctuations incurred by an optical beam travelling through free space, especially a turbulent atmosphere. A transmitting station transmits a plurality of uniquely tagged optical beams through free space. The plurality of uniquely tagged optical beams are received at a receiving station, where a parameter of each uniquely tagged optical beam is quantified. Information associated with the quantified parameter for each uniquely tagged optical beam is then sent back to the transmitting station via a wireless feedback link. Using the information, the transmitting station adjusts at least one uniquely tagged optical beam to compensate for phase fluctuations.

Abstract: A multiple-fiber, stretched, fused and cleaved coupler designed to act as an output window to a fiber laser array or fiber-coupled laser array, in which the stretch, length and/or position of the fibers is chosen facilitate the in-phase oscillation of the lasers in the array. The in-phase oscillation of the lasers is facilitated by making one or more of the fibers interferometrically dark and having a different propagation constant than the other fibers. The other fibers, the interferometrically lit ones, are made to have fairly uniform intensity under the same collimated illumination.

Abstract: A phase-conjugate mirror has a length of hollow core photonic crystal multi-spatial mode, polarization-maintaining fiber disposed in a vessel, with a compressible and preferably gaseous medium, such as Xe or CH4, occupying the hollow core of the of hollow core photonic crystal fiber and surrounding the exterior of the hollow core photonic crystal fiber. At least one sealed window is provided in the vessel, the at least one sealed window being optically coupled to at least one end of the length of hollow core photonic crystal fiber.

Abstract: A waveguide is fabricated by first preparing two waveguide precursor pieces. Each waveguide precursor piece includes a single-crystal substrate, and an epitaxial coating layer of an oxide coating material on the substrate. The oxide substrate material preferably comprises yttrium as a substrate-material cation, and the oxide coating material preferably comprises a coating-material cation selected from the group consisting of ytterbium, thulium, erbium, and holmium. The two substrates are placed together with the coating layers in contact to form a precursor structure. The precursor structure is heated to an elevated diffusion temperature so that the coating layers bond together and the coating materials and the respective substrate materials interdiffuse to form the waveguide having an interdiffused region. A laser beam may be directed through the interdiffused region, while the interdiffused region is optionally optically pumped through one or both of the substrates.

Abstract: A laser system for producing a laser beam, the laser system having top and bottom heat-sinking bars forming the structure of the laser system and plurality of disks comprising a laser material mounted on both the bottom heat-sinking bar and the top heat-sinking bar. Also mounted on both heat-sinking bars is a plurality of pump diode bars. Each pump diode bar is preferably mounted opposite a corresponding laser disk on the opposite heat-sinking bar. The pump diode bars and the disks are symmetrically mounted on the top and bottom heat-sinking bars, so that each heat-sinking bar has an alternating pattern of pump diode bars and laser disks. The laser system is configured such that the lasing beams impinge on the disks with an incidence angle far off normal.

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: A laser apparatus, comprising a layer fabricated of a lasing medium, the layer having a top surface and a bottom surface, and a first substrate layer fabricated of a laser-inactive material, the first substrate being diffusion-bonded to the layer of lasing medium, wherein the lasing medium comprises a crystalline, polycrystalline or glass material doped with ions. The lasing medium selected for fabrication of the laser apparatus of this invention comprises neodymium-doped yttrium vanadate material and laser-inactive material of the substrate comprises an yttrium-aluminate or yttrium vanadate material. The layers of material are oriented so that the thermal expansion coefficients along the crystallographic axes of the materials match or nearly match.

Abstract: A laser apparatus having multiple laser devices coupled together. The laser devices comprise optical fibers with laser active regions. Each of the fibers has a reflector disposed at one end and is connected to a combiner on the other end. A laser pump device for each fiber provides pump energy to the laser active regions. Light propagating in the fibers interacts so as to form inphase states. The array of fibers may be coupled either in pairs or altogether between the reflector and the laser active region.

Abstract: A fiber optic apparatus formed by fusing together multiple optical fibers and stretching the fused optical fibers to form a tapered portion. The tapered portion is cleaved or cut and polished to form a facet at which an optical beam is received or transmitted.

Abstract: A method and apparatus for compensating for phase fluctuations incurred by an optical beam travelling through free space, especially a turbulent atmosphere. A transmitting station transmits a plurality of uniquely tagged optical beams through free space. The plurality of uniquely tagged optical beams are received at a receiving station, where a parameter of each uniquely tagged optical beam is quantified. Information associated with the quantified parameter for each uniquely tagged optical beam is then sent back to the transmitting station via a wireless feedback link. Using the information, the transmitting station adjusts at least one uniquely tagged optical beam to compensate for phase fluctuations.