Abstract: An IR laser source providing light in the IR spectrum, the laser source comprising a pump laser operating at a frequency equivalent to wavelength shorter than 2 ?m and at a predetermined power, and an optic fiber coupled to the pump laser. The optic fiber has at least a section of a hollow core photonic crystal fiber, the at least a section of hollow core photonic crystal fiber being designed to have at least a passband in the IR spectrum and being filled with a molecular gas for triggering at least one Stoke's shift in the light entering the at least a section of hollow core photonic crystal fiber for the particular power of the pump laser, the at least one Stoke's shift be selected to cause the light entering the at least a section of hollow core photonic crystal fiber to shift in frequency into the passband in the IR spectrum of the hollow core photonic crystal fiber.

Abstract: An IR laser source providing light in the IR spectrum, the laser source comprising a pump laser operating at a frequency equivalent to wavelength shorter than 2 ?m and at a predetermined power, and an optic fiber coupled to the pump laser. The optic fiber has at least a section of a hollow core photonic crystal fiber, the at least a section of hollow core photonic crystal fiber being designed to have at least a passband in the IR spectrum and being filled with a molecular gas for triggering at least one Stoke's shift in the light entering the at least a section of hollow core photonic crystal fiber for the particular power of the pump laser, the at least one Stoke's shift be selected to cause the light entering the at least a section of hollow core photonic crystal fiber to shift in frequency into the passband in the IR spectrum of the hollow core photonic crystal fiber.

Abstract: An optical metrology system having an optical metrology sensor assembly and a target is disclosed. The optical metrology sensor assembly transmits a light beam to the target and then uses the reflected beam from the target to determine the position of the target in three dimensions. The optical metrology sensor can comprise a light source, a ranging device, and a two-dimensional sensor. The optical metrology system is suitable for applications such as determining the position, orientation, and shape of a spacecraft antenna, so as to facilitate movement thereof to enhance operation of the antenna.

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: An optical metrology system having an optical metrology sensor assembly and a target is disclosed. The optical metrology sensor assembly transmits a light beam to the target and then uses the reflected beam from the target to determine the position of the target in three dimensions. The optical metrology sensor can comprise a light source, a ranging device, and a two-dimensional sensor. The optical metrology system is suitable for applications such as determining the position, orientation, and shape of a spacecraft antenna, so as to facilitate movement thereof to enhance operation of the antenna.

Abstract: A high power Er-doped fiber amplifier/laser system includes a cladding-pumped fiber grating laser that emits an output beam at a wavelength that falls within an absorption band of erbium. The fiber grating laser output beam is used as the pumping source for an Er-doped fiber amplifier or laser. Because the output from the fiber grating laser falls within one of the erbium absorption bands, the amplifier or laser may be directly pumped with the fiber grating laser's output without the need for co-doping. In a preferred embodiment, the fiber grating laser is a 980 nm ytterbium-doped fiber grating laser that is cladding-pumped with a multi-transverse mode diode laser array. The Yb-doped fiber grating laser and the Er-doped fiber amplifier/laser are preferably spliced directly to an input and output arm of a WDM fiber coupler, respectively.

Abstract: A simple, low-cost deformation mechanism and method produces submicrometer increments of motion, to precisely stretch and compress fibers containing optical gratings in order to achieve a desired length and period. Such a "tunable" fiber can be used to, for example, produce an optical filter or to "match" two fiber lasers, thus enabling their use in a coherent detection system. Two beams, parallel to and opposing each other, are joined at two places. A screw is positioned between the beams such that a force is exerted on both beams simultaneously when the screw is rotated, deforming both beams. Motion reduction is provided by sharing the screw's movement between the two beams, and is further enhanced by making one beam thicker than the other. Two fibers are secured into grooves provided on one of the beams. By rotating the screw to increase or decrease the deformation, the fibers and their respective gratings are stretched or compressed.

Abstract: A high-Q pump cavity is formed from undoped crystal pieces that are diffusion bonded to a doped core of the same crystal host material. The resulting monolithic pump cavity has 2 opposing convex-curved sides which have a highly-reflective coating on their outer surfaces, except in narrow slit-shaped areas on each curved side through which laser-diode-supplied pump light enters the cavity. The curvature of the two curved sides is such that nearly all the pump light rays that pass through the slit-shaped areas are focussed by the curvature onto the doped core, and rays that enter the cavity are redirected through the doped core many times, resulting in efficient, uniform absorption. The cavity has two opposing flat sides that interface with metal heat sink blocks to facilitate the removal of internally-generated heat. Thermally induced astigmatic lensing caused by this heat is countered by cavity design in which the core shape and the dimensions of the cavity minimize this astigmatism.

Abstract: A narrow bandwidth Bragg grating reflector comprises at least two Bragg reflection gratings positioned to form a Fabry-Perot etalon, with an optical gain medium between them. The etalon formed by the Bragg gratings has a reflection frequency spectrum that exhibits a plurality of primary peaks and nulls. The distance between the Bragg gratings is adjusted so that a predetermined design frequency falls within the bandwidth of one of the nulls, and the optical gain medium is chosen to provide optical gain for light at the design frequency. This establishes a secondary reflection peak in the Bragg grating etalon, centered on the design frequency, with a bandwidth that is narrower than those of the individual Bragg gratings and primary reflection peaks. In a preferred embodiment, the Bragg gratings are formed in the core of an optical fiber that is doped to provide optical gain at the predetermined optical frequency.

Abstract: A method for forming an index grating in an optical waveguide, such as an optical fiber, with precise control over the grating's period, cross-sectional shape and length. A single writing beam is passed through an optical grating mask, such as a phase mask. A photosensitive waveguide is spaced from the optical grating by a distance that corresponds to an integer fraction of the Talbot self-imaging distance, so that the optical grating (or a desired transformation of it) is imaged in the waveguide core. The grating image has substantially the same cross-sectional shape, period and length as the portion of the optical grating that is illuminated by the writing beam. Thus, an index grating that substantially replicates the cross-sectional shape, period and length of the optical grating mask, which preferably has a substantially square-wave shaped cross-section, is written in the waveguide core.