Abstract: An optical fiber including: (i) a silica based, rare earth doped core having a first index of refraction n1; (ii) a silica based inner cladding surrounding the core and having a second index of refraction n2, such that n1>n2, said inner cladding having a plurality of air holes extending longitudinally through the length of said optical fiber; (iii) a silica based outer cladding surrounding said inner cladding and having a third index of refraction n3, such that n2>n3, wherein said optical fiber supports a single polarization mode within the operating wavelength range.

Abstract: An athermal optical device and a method for producing the device, such as an athermal optical fiber reflective grating, are described. The athermal optical fiber reflective grating device comprises a negative expansion substrate, an optical fiber mounted on the substrate surface, and a grating defined in the optical fiber. The method for producing the athermal optical fiber reflective grating device comprises providing a negative expansion substrate, mounting an optical fiber with at least one reflective grating defined therein onto the substrate upper surface, and affixing the optical fiber to the substrate at at least two spaced apart locations.

Abstract: According to one aspect of the present invention the optical interrogation system comprises: (i) an optical sensor capable of immobilizing biological, bio-chemical and/or chemical substance; and (ii) an optical isolator that filters and eliminates parasitic reflections introduced by the optical sensor. In some embodiments the optical sensor includes a GCW with a surface having a sensing region capable of immobilizing biological, bio-chemical or chemical substances includes, and the optical interrogation system includes an optical detection system for monitoring this sensing region, the optical detection system comprising a light source, an optical delivery system, and a detection instrument.

Abstract: An optical system comprises an optical fiber with gain producing core with an index of refraction n1, surrounded by at least one cladding with an index of refraction n2, said cladding including at least one index reduced area with an index of refraction n2, such that n1>n2>n2, the core propagating a signal at a spatial fundamental mode at a signal wavelength ?1 and at a power level sufficient to generate optical power at a wavelength ?2, where ?2>?1, and the at least one index reduced area in combination with the core provide has at least one cut-off fundamental spatial mode wavelength ?C, and ?1<?C and ?2>?C.

Abstract: The optical fiber comprises: (a) a core having a refractive index profile and a centerline; and (b) a cladding layer surrounding and directly adjacent the core; wherein core includes updoping material and is doped with F in at least one region of the core, such that either: (a) the average longitudinal acoustic wave velocity within the core is within 0.05% of the longitudinal acoustic wave velocity within the cladding; or (b) the longitudinal acoustic wave velocity at one region of the core is different from the longitudinal velocity at another region of the core by at least 0.2%.

Abstract: A method for measuring longitudinal variation in chromatic dispersion in an optical fiber, comprising: (i) launching into a first end and a second end of optical fiber an optical signal at a wavelength ?1 to collect backscatter power P(z) for different positions z within said optical fiber and providing measured OTDR backscatter traces; (ii) deriving from the measured OTDR backscatter traces at the single OTDR wavelength ?1 either (a) the longitudinal MFD(z) data or (b) the relative MFD data; and (iii) calculating estimated longitudinal dispersion D(z) from the longitudinal MFD(z) data or the relative MFD data, without utilizing any other wavelength data.

Abstract: A solid oxide fuel cell device incorporates a sealing material resistant to hydrogen gas permeation at a sealing temperature in the intermediate temperature range of 600° C.–900° C., the seal having a CTE in the 100×10?7/° C. to 120×10?7/° C., wherein the sealing material comprises in weight %, of: (i) a 80 wt % to 100 wt % glass frit, the glass frit itself having a composition comprising in mole percent of: SiO2 15–65; Li2O 0–5; Na2O 0–5; K2O 0–10; MgO 0–5; CaO 0–32; Al2O3 0–10; B2O3 0–50; SrO 0 to 25, wherein the total amount of alkalis is less than 10 mole %; and (ii) zirconia or leucite addition 0 wt % to 30 wt.

Abstract: An optical fiber, comprising: (i) a rare earth doped silica based elongated core with a first refractive index (n1) with an aspect ratio of 1:5 to 1; (ii) a silica based moat abutting and at least substantially surrounding the core, the moat having a refractive index n2, wherein n2<n1; (iii) a silica based inner cladding surrounding the moat, the inner cladding having a third refractive index (n3), wherein n1>n3; and n3>n2; (iv) a silica based outer cladding surrounding said inner cladding, the outer cladding having a fourth refractive index (n4), such that n4<n3; the optical fiber exhibits single polarization at the operating wavelength band.

Abstract: An optical fiber, comprising: a central core having a maximum dimension (A) greater than a minimum dimension (B) and a substantially elliptical shape, the fiber having at least one air hole positioned each opposite side of the central core wherein the optical fiber exhibits (i) single polarization propagation within a single polarization band and (ii) polarization maintaining property, such that the fiber beat length normalized at 1550 nm is less than 10 mm; and the polarization maintaining band is situated within wavelengths which are (a) adjacent to and below the single polarization band; and (b) above the higher order mode cutoff wavelength.

Abstract: An optical fiber that includes a central core having a maximum dimension (A) greater than a minimum dimension (B), preferably with an aspect ratio greater than 1.5, the fiber having at least one air hole positioned on opposite sides of the central core and extending along the fiber's length wherein the fiber supports a single polarization mode within an operating wavelength band. The fiber may be coupled to optical components in systems to provide single polarization in the band. A method for manufacturing the fiber is also provided.

Abstract: Disclosed is an optical fiber (20) having a centermost laterally-elongated core (30) having a short dimension (a), a long dimension (b) and a first refractive index (n1), a moat (40) surrounding the central laterally-elongated core, the moat (40) having a second refractive index (n2), an outer dimension (c) and an outer dimension (d), and a cladding (50) surrounding the moat (40), the cladding (50) having a third refractive index (n3), wherein n1>n3>n2, a ratio of b/a is between 1.5 and 5.0, and a ratio of d/a is between 2.0 and 7.0. The fiber exhibits polarization maintaining properties in a PMB situated below (i.e., at shorter wavelength than SPB), such that beat length normalized to 1550 nm wavelength is preferably less than 10 mm. The fiber (20) may be coupled to optical components in apparatus where single polarization or polarization maintaining properties are desired.

Abstract: An optical waveguide fiber comprises: (a) a core with a refractive index profile having, a radius, an alpha and a relative refractive index characterized by delta % that varies along the radius; (b) at least one cladding surrounding the core; wherein the alpha is less than 2.5, peak refractive index delta % is between 0.34% and 0.4%, the relative refractive index is less than 0.01% for all radii greater than 7 ?m, and this optical waveguide fiber has a mode field diameter MFD at a wavelength of 1310 nm of no more than 9.54 ?m, and attenuation less than: (a) 0.329 dB/km at a wavelength of 1310 nm, (b) 0.290 dB/km at a wavelength of 1383 nm, (c) 0.255 dB/km at a wavelength of 1410 nm, and (d) 0.189 dB/km at a wavelength of 1550 nm.

Abstract: According to the present invention the optical fiber includes a core with a first refractive index (n1) and the innermost core region with the refractive index n0, a cladding surrounding the core, the cladding having a third refractive index (n3), wherein n1>n3 and n0<n1. According to some of the embodiments the optical fiber may also include a moat surrounding and abutting the core and situated between the core and the cladding, the moat having a second refractive index (n2), wherein n3>n2. It is preferable that at least one of the core, innermost core region and/or moat has a non-circular shape.

Abstract: An optical fiber comprising: (i) a silica based, rare earth doped core having a first index of refraction n1; (ii) a silica based inner cladding surrounding the core having a second index of refraction n2, such that n1>n2; (iii) a silica based outer cladding surrounding the inner cladding having a third index of refraction n3 such that n2>n3, wherein inner cladding diameter is at least 125 ?m.

Abstract: A supercontinuum light emitting device comprises an effectively CW light source producing light of wavelength ?1 within a specified bandwidth and a nonlinear fiber optically coupled to the light source. The nonlinear fiber has a plurality of fiber segments with different zero dispersion wavelengths ?oi, where each successive fiber segment has zero dispersion wavelength ?oi which is larger than the zero dispersion wavelength of the preceding fiber and the zero dispersion wavelength of the first fiber segment is within ±20 nm of ?1.

Abstract: An optical waveguide fiber having a high threshold for stimulated Brillouin scattering. According to some embodiments of the invention, the optical fiber comprises: (a) a rare earth doped core having a refractive index profile and a centerline, the core including at least two adjacent core regions including different amounts of updopants, such that the longitudinal acoustic field velocities within the two core regions differ by at least 0.2%; and (b) a cladding layer surrounding and directly adjacent the core. The said fiber has MFD of greater than 12 ?m and delta % difference between the peak core delta and the cladding of less than 0.3%.

Abstract: Methods, apparatus and precursors for producing substantially water-free silica soot, preforms and glass. The methods and apparatus make substantially water-free fused silica preforms or glass by removing water as a reaction product, removing water from the atmosphere, removing water from the transport process, or combinations thereof. In a first embodiment, substantially water-free soot, preforms or glass are achieved by using a hydrogen-free fuel, such as carbon monoxide, in the deposition process. In another embodiment, a soot producing burner has parameters that enable operation on a substantially hydrogen-free fuel. End burners, which minimize water production, are also described. Such water-free methods are useful in depositing fluorine-doped soot because of the low water present and the efficiency in which fluorine is incorporated. In another embodiment, glassy barrier layer methods and apparatus are described for minimizing dopant migration, especially fluorine.

Abstract: The present invention provides devices and methods for dispersion compensation. According to one embodiment of the invention, a dispersion compensating device includes a negative dispersion fiber having an input configured to receive the optical signal, the negative dispersion fiber having a length and dispersion sufficient to remove any positive chirp from each wavelength channel of the optical signal, thereby outputting a negatively chirped optical signal; an amplifying device configured to amplify the negatively chirped optical signal; and a nonlinear positive dispersion fiber configured to receive the negatively chirped optical signal. The devices of the present invention provide broadband compensation for a systems having a wide range of variable residual dispersions.

Abstract: The present invention provides devices and methods for dynamic dispersion compensation. According to one embodiment of the invention, a dispersion compensating device includes a negative dispersion fiber having an input configured to receive the optical signal, the negative dispersion fiber having a length and dispersion sufficient to remove any positive chirp from each wavelength channel of the optical signal, thereby outputting a negatively chirped optical signal; an amplifying device configured to amplify the negatively chirped optical signal; and a nonlinear positive dispersion fiber configured to receive the negatively chirped optical signal. The devices of the present invention provide broadband compensation for systems having a wide range of variable residual dispersions.

Abstract: An optical fiber comprising: (i) a central core having a relative refractive index delta ?C; (ii) a multi-pedestal region in contact with and surrounding the core, said multi-pedestal region having an outer radius of less than 25 ?m and at least two pedestals, each of the pedestals being in contact and adjacent to at least one other pedestal, each of the pedestals having a relative refractive index ?ped lower than ?C, at least one of the pedestals having ?ped value higher than 0.2%; and (iii) another region in contact and surrounding the multi-pedestal region, the other region having a relative refractive index delta which is lower than that of any pedestal.