Abstract: A Fourier-Transform Infrared (FTIR) spectrometer for operation in the mid- and long-wave infrared region (about 2-15 micron wavelengths) is disclosed. The FTIR spectrometer is composed of IR-transmitting fiber and uses a broadband IR source. A fiber stretcher is provided to provide a path difference between a first path and a second path having a sample associated therewith. Stretching of the fiber provides a path difference sufficient to generate an interferogram that can subsequently be analyzed to obtain information about a sample. A method for use of the apparatus of the invention is also disclosed. The method involves stretching of an IR-transmitting fiber to create a path difference sufficient to generate an interferogram. Various aspects of these features enable the construction of compact, portable spectrometers.

Abstract: A functionally doped polycrystalline ceramic laser medium and method of making thereof are provided. The medium includes a solid state polycrystalline Ytterbium doped Yttria or Scandia (Yb:Y2O3 or Yb:Sc2O3) laser medium with a discrete or continuous gradient doping profile and methods for manufacturing the same. The doping profile can be two- or three-dimensional and can vary depending upon the laser geometry, the pumping scheme, and the benefits to be desired from the laser medium's structure. The grading direction can be linear, axial, radial, or any combination thereof. The material can be made from a combination of doped and undoped solid shapes, loose powders, and green shapes, and can be diffusion bonded or densified to a desired final shape using techniques such as pressureless sintering, hot pressing, hot forging, spark plasma sintering, and hot isostatic pressing (HIPing), or their combinations.

Abstract: A functionally doped polycrystalline ceramic laser medium and method of making thereof are provided. The medium includes a solid state polycrystalline Ytterbium doped Yttria or Scandia (Yb:Y2O3 or Yb:Sc2O3) laser medium with a discrete or continuous gradient doping profile and methods for manufacturing the same. The doping profile can be two- or three-dimensional and can vary depending upon the laser geometry, the pumping scheme, and the benefits to be desired from the laser medium's structure. The grading direction can be linear, axial, radial, or any combination thereof. The material can be made from a combination of doped and undoped solid shapes, loose powders, and green shapes, and can be diffusion bonded or densified to a desired final shape using techniques such as pressureless sintering, hot pressing, hot forging, spark plasma sintering, and hot isostatic pressing (HIPing), or their combinations.

Abstract: A chalcogenide multi-clad optical fiber having a core, a first cladding and one or more subsequent claddings including a chalcogenide glass. The optical fiber may be capable of transmitting visible and inferred light and may be used for a wide variety of semiconductor applications.

Abstract: An optical fiber having microstructured terminal end suitable for reducing Fresnel losses. In an exemplary embodiment, the microstructured surface includes a plurality of protrusions, recesses or combinations thereof that effectively and incrementally change the refractive index of the terminal end of the optical fiber such that the refractive index is gradually drawn closer to the refractive index value of the surrounding environmental medium.

Abstract: Fiber optic amplification in a spectrum of infrared electromagnetic radiation is achieved by creating a chalcogenide photonic crystal fiber (PCF) structure having a radially varying pitch. A chalcogenide PCF system can be tuned during fabrication of the chalcogenide PCF structure, by controlling, the size of the core, the size of the cladding, and the hole size to pitch ratio of the chalcogenide PCF structure and tuned during exercising of the chalcogenide PCF system with pump laser and signal waves, by changing the wavelength of either the pump laser wave or the signal wave, maximization of nonlinear conversion of the chalcogenide PCF, efficient parametric conversion with low peak power pulses of continuous wave laser sources, and minimization of power penalties and minimization of the need for amplification and regeneration of pulse transmissions over the length of the fiber, based on a dispersion factor.

Abstract: A photonic band gap fiber and method of making thereof is provided. The fiber is made of a germanate glass comprising at least 30 mol % of a germanium oxide and has a longitudinal central opening, a microstructured region having a plurality of longitudinal surrounding openings, and a jacket. The air fill fraction of the microstructured region is at least about 90%. The fiber may be made by drawing a preform into a fiber, while applying gas pressure to the microstructured region. The air fill fraction of the microstructured region is changed during the drawing.

Abstract: The present invention is generally directed to a device comprising multiple specialty glass optical fibers that combines several different mid-infrared optical signals from multiple optical fibers into one signal in a single optical fiber. In addition, the present invention provides for a method of making the device.

Abstract: A wavelength converter comprising an arsenic sulfide (As—S) chalcogenide glass fiber coupled to an optical parametric oscillator (OPO) crystal and a laser system using an OPO crystal coupled to an As—S fiber are provided. The OPO receives pump laser radiation from a pump laser and emits laser radiation at a wavelength that is longer than the pump laser radiation. The laser radiation that is emitted from the OPO is input into the As—S fiber, which in turn converts the input wavelength from the OPO to a desired wavelength, for example, a wavelength beyond about 4.4 ?m. In an exemplary embodiment, the OPO comprises a periodically poled lithium niobate (PPLN) crystal. The As—S fiber can include any suitable type of optical fiber, such as a conventional core clad fiber, a photonic crystal fiber, or a microstructured fiber.

Abstract: A doped glass composition is provided. A base glass is doped with rare earth ions Terbium Tb3+ and Europium Eu3+ to produce a glass that reduces the transmission of short-wave infrared radiation therethrough without reducing the transmission of visible light. A base glass composition is doped with Tb3+ and Eu3+ ions to an appreciable concentration, in some embodiments in excess of 5 mol % and in other embodiments to a concentration in excess of 1 mol %. A suitable glass for doping according to the present invention includes any glass that can accept rare earth ions at appreciable densities such as the densities described above, and can include oxide-based, fluoride-based, and chalcogenide-based glasses. The doped glass attenuates transmission of short-wave infrared radiation having wavelengths of about 1.8 ?m to about 2.5 ?m and does not reduce transmission of visible light having wavelengths from about 0.4 ?m to about 0.8 ?m.

Abstract: A wavelength converter comprising an arsenic sulfide (As—S) chalcogenide glass fiber coupled to an optical parametric oscillator (OPO) crystal and a laser system using an OPO crystal coupled to an As—S fiber are provided. The OPO receives pump laser radiation from a pump laser and emits laser radiation at a wavelength that is longer than the pump laser radiation. The laser radiation that is emitted from the OPO is input into the As—S fiber, which in turn converts the input wavelength from the OPO to a desired wavelength, for example, a wavelength beyond about 4.4 ?m. In an exemplary embodiment, the OPO comprises a periodically poled lithium niobate (PPLN) crystal. The As—S fiber can include any suitable type of optical fiber, such as a conventional core clad fiber, a photonic crystal fiber, or a microstructured fiber.

Abstract: A photonic band gap fiber and method of making thereof is provided. The fiber is made of a germanate glass comprising at least 30 mol % of a germanium oxide and has a longitudinal central opening, a microstructured region having a plurality of longitudinal surrounding openings, and a jacket. The air fill fraction of the microstructured region is at least about 90%. The fiber may be made by drawing a preform into a fiber, while applying gas pressure to the microstructured region. The air fill fraction of the microstructured region is changed during the drawing.

Abstract: A transparent polycrystalline ceramic having scattering and absorption loss less than 0.2/cm over a region comprising more than 95% of the originally densified shape and further provides a process for fabricating the same by hot pressing. The ceramic can be any suitable ceramic such as yttria (Y2O3) or scandia (Sc2O3) and can have a doping level of from 0 to 20% and a grain size of greater than 30 ?m, although the grains can also be smaller than 30 ?m. In a process for making a transparent polycrystalline ceramic in accordance with the present invention, ceramic nanoparticles can be coated with a sintering aid to minimize direct contact of adjacent ceramic powder particles and then baked at high temperatures to remove impurities from the coated particles. The thus-coated particles can then be densified by hot pressing into the final ceramic product. The invention further provides a transparent polycrystalline ceramic solid-state laser material and a laser using the hot pressed polycrystalline ceramic.

Abstract: A Fourier-Transform Infrared (FTIR) spectrometer for operation in the mid- and long-wave infrared region (about 2-15 micron wavelengths) is disclosed. The FTIR spectrometer is composed of IR-transmitting fiber and uses a broadband IR source. A fiber stretcher is provided to provide a path difference between a first path and a second path having a sample associated therewith. Stretching of the fiber provides a path difference sufficient to generate an interferogram that can subsequently be analyzed to obtain information about a sample. A method for use of the apparatus of the invention is also disclosed. The method involves stretching of an IR-transmitting fiber to create a path difference sufficient to generate an interferogram. Various aspects of these features enable the construction of compact, portable spectrometers.

Abstract: A wavelength converter comprising an arsenic sulfide (As—S) chalcogenide glass fiber coupled to an optical parametric oscillator (OPO) crystal and a laser system using an OPO crystal coupled to an As—S fiber are provided. The OPO receives pump laser radiation from a pump laser and emits laser radiation at a wavelength that is longer than the pump laser radiation. The laser radiation that is emitted from the OPO is input into the As—S fiber, which in turn converts the input wavelength from the OPO to a desired wavelength, for example, a wavelength beyond about 4.4 ?m. In an exemplary embodiment, the OPO comprises a periodically poled lithium niobate (PPLN) crystal. The As—S fiber can include any suitable type of optical fiber, such as a conventional core clad fiber, a photonic crystal fiber, or a microstructured fiber.

Abstract: A waveguide amplifier, disposed on a substrate, composed of sputtered film of chalcogenide glass doped with Erbium is disclosed. The amplifier includes a substrate, a thick film of chalcogenide glass disposed on the substrate, a pumping device, and an optical combining device, wherein the waveguide is operable to amplify the optically combined signal. This type of amplifier has been shown to be compact and cost-effective, in addition to being transparent in the mid-IR range as a result of the low phonon energy of chalcogenide glass.

Abstract: A hollow core photonic bandgap chalcogenide glass fiber includes a hollow core for passing light therethrough, a Raman active gas disposed in said core, a microstructured region disposed around said core, and a solid region disposed around said microstructured region for providing structural integrity to said microstructured region. A coupler can introduce at least one light signal into the hollow core of the chalcogenide photonic bandgap fiber. The method includes the steps of introducing a light beam into a hollow core chalcogenide photonic bandgap glass fiber filled with a Raman active gas disposed in the core, conveying the beam through the core while it interacts with the gas to form a Stokes beam of a typically higher wavelength, and removing the Stokes beam from the core of the fiber.

Abstract: A photonic band gap fiber and method of making thereof is provided. The fiber is made of a non-silica-based glass and has a longitudinal central opening, a microstructured region having a plurality of longitudinal surrounding openings, and a jacket. The air fill fraction of the microstructured region is at least about 40%. The fiber may be made by drawing a preform into a fiber, while applying gas pressure to the microstructured region. The air fill fraction of the microstructured region is changed during the drawing.