Abstract: The methods disclosed herein include forming an expanded core in an optical fiber with a glass core having a core dopant and a core outer surface, and a glass cladding immediately surrounding the core and having a flat glass-portion surface closest to the core outer surface at a first core spacing S1. The methods include applying heat to a section of the optical fiber to cause the glass core to expand toward the flat glass-portion surface due to thermal diffusion of the core dopant. The methods also include terminating the application of heat to define the expanded core in the heated section of the optical fiber. The expanded core defines an evanescent coupling region having a second core spacing 0?S2<S1 and an adiabatic transition region between the core and the evanescent coupling region of the expanded core.

Abstract: Preparation of halogen-doped silica is described. The preparation includes doping silica with high halogen concentration, sintering halogen-doped silica to a closed-pore state, and subjecting the closed-pore silica body to a thermal treatment process and/or a pressure treatment process. The temperature of thermal treatment is sufficiently high to facilitate reaction of unreacted doping precursor trapped in voids or interstices of the glass structure, but is below temperatures conducive to foaming. Core canes or fibers drawn from halogen-doped silica subjected to the thermal treatment and/or pressure treatment show improved optical quality and possess fewer defects. The thermal treatment and/or pressure treatment is particularly advantageous when used for silica doped with high concentrations of halogen.

Abstract: A method of cleaving an optical fiber comprises inserting the optical fiber through a bore of a holding member, securing the optical fiber to the holding member with a bonding agent, operating at least one laser to emit at least one laser beam, and directing the at least one laser beam from the at least one laser to the end face of the holding member. At least a portion of the at least one laser beam reflects off the end face of the holding member and is thereafter incident on an end portion of the optical fiber. The at least one laser beam cleaves the end portion of the optical fiber less than 20 ?m from the end face of the holding member. Related systems are also disclosed.

Abstract: A coupled-core multicore optical fiber has a plurality of cores that are doped with alkali metals or chlorine to achieve low attenuation and a large effective area. The cores may be embedded in a common cladding region that may be fluorine doped. The cores may also be doped with chlorine, either with the alkali metals described above or without the alkali metals.

Abstract: A high-density optical fiber ribbon is formed by two or more cladding-strengthened glass optical fibers each having an outer surface and that do not individually include a protective polymer coating. A common protective coating substantially surrounds the outer surfaces of the two or more cladding-strengthened glass optical fibers so that the common protective coating is common to the two or more cladding-strengthened glass optical fibers. A fiber ribbon cable is formed by adding a cover assembly to the fiber ribbon. A fiber ribbon interconnect is formed adding one or more optical connectors to the fiber ribbon or fiber ribbon cable. Optical data transmission systems that employ the fiber ribbon to optically connect to a photonic device are also disclosed. Methods of forming the cladding-strengthened glass optical fibers and the high-density optical fiber ribbons are also disclosed.

Abstract: An optical fiber having a core comprising silica and greater than 1.5 wt % chlorine and less than 0.5 wt % F, said core having a refractive index ?1MAX, and an inner cladding region having refractive index ?2MIN surrounding the core, where ?1MAX>?2MIN.

Abstract: An optical fiber is provided that includes a core region, a cladding region having a radius less than about 62.5 microns; a polymer coating comprising a high-modulus layer and a low-modulus layer, wherein a thickness of the low-modulus inner coating layer is in a range of 4 microns to 20 microns, the modulus of the low-modulus inner coating layer is less than or equal to about 0.35 MPa, a thickness of the high-modulus coating layer is in a range of 4 microns to 20 microns, the modulus of the high-modulus inner coating layer is greater than or equal to about 1.6 GPa, and wherein a puncture resistance of the optical fiber is greater than 20 g, and wherein a microbend attenuation penalty of the optical fiber is less than 0.

Abstract: Multicore optical fibers with low bend loss, low cross-talk, and large mode field diameters In some embodiments a circular multicore optical fiber includes a glass matrix; at least 3 cores arranged within the glass matrix, wherein any two cores have a core center to core center spacing of less than 29 microns; and a plurality of trench layers positioned between a corresponding core and the glass matrix, each trench layer having an outer radius of less than or equal to 14 microns and a trench volume of greater than 50% ? micron2; wherein the optical fiber has a mode field diameter of greater than about 8.2 microns at 1310 nm, and wherein the optical fiber has an outer diameter of less than about 130 microns.

Abstract: The present disclosure relates to a thin coated optical fiber that enables connector assembly without stripping the optical fiber.

Abstract: A single mode optical fiber is provided that includes a core region having an outer radius ri and a maximum relative refractive index ?1max. The single mode optical fiber further includes a cladding region surrounding the core region, the cladding region includes a depressed-index cladding region, a relative refractive index ?3 of the depressed-index cladding region increasing with increased radial position. The single mode optical fiber has a bend loss at 1550 nm for a 15 mm diameter mandrel of less than about 0.75 dB/turn, a bend loss at 1550 nm for a 20 mm diameter mandrel of less than about 0.2 dB/turn, and a bend loss at 1550 nm for a 30 mm diameter mandrel of less than 0.005 dB/turn. Additionally, the single mode optical fiber has a mode field diameter of 9.0 microns or greater at 1310 nm wavelength.

Abstract: A quantum communications system includes a quantum key generation system having a photonic quantum bit generator, a dispersion compensating optical fiber link, and a photon detector unit and a communications network having a signal generator, a signal channel, and a signal receiver. The dispersion compensating optical fiber link extends between and optically couples the photonic quantum bit generator and the photon detector unit. Further, the dispersion compensating optical fiber link is structurally configured to induce dispersion at an absolute dispersion rate of about 9 ps/(nm)km or less and induce attenuation at an attenuation rate of about 0.18 dB/Km or less such that the quantum key bit information of a plurality of photons output by the one or more photonic quantum bit generators is receivable at the photon detector unit at a bit rate of at least about 10 Gbit/sec.

Abstract: A single mode optical fiber is provided that includes a core region and a cladding region, the cladding region including a depressed-index cladding region, a first outer cladding region, and a second outer cladding region. The first outer cladding region has a lower relative refractive than the second outer cladding region. The single mode optical fiber has a bend loss at 1550 nm for a 15 mm diameter mandrel of less than about 0.75 dB/turn, has a bend loss at 1550 nm for a 20 mm diameter mandrel of less than about 0.2 dB/turn, and a bend loss at 1550 nm for a 30 mm diameter mandrel of less than about 0.005 dB/turn. Additionally, the single mode optical fiber has a mode field diameter of about 9.0 microns or greater at 1310 nm wavelength and a cable cutoff of less than or equal to about 1260 nm.

Abstract: A quantum communications system includes a quantum key generation system having a photonic quantum bit generator, a low loss dispersion limiting fiber having a length L, for example greater than 200 km, and a photon detector unit and a communications network having a signal generator, a signal channel, and a signal receiver. The low loss dispersion limiting fiber extends between and optically couples the photonic quantum bit generator and the photon detector unit. Further, the low loss dispersion limiting fiber is structurally configured to limit dispersion at an absolute dispersion rate of about 9 ps/(nm)km or less, and preferably 0.5 ps/(nm)km or less, and induce attenuation at an attenuation rate of about 0.175 dB/km or less such that the quantum key bit information of a plurality of photons output by the one or more photonic quantum bit generators is receivable at the photon detector unit at a bit rate of at least 10 Gbit/sec.

Abstract: The optical fibers disclosed is a single mode optical fiber having a core region and a cladding region surrounding and directly adjacent to the core region. The core region can have a radius r1 in a range from 3.0 microns to 6.0 microns and a core volume V1 less than 6.0%-micron2. The cladding region can include a first outer cladding region and a second outer cladding region surrounding and directly adjacent to the first outer cladding region. The first outer cladding region can have a radius r4a, the second outer cladding region can have a radius r4b less than or equal to 65 microns and comprising silica based glass doped with titania. The disclosed single mode optical fiber can have a fiber cutoff wavelength ?CF less than 1530 nm.

Abstract: A system and method for nitridizing a glass article includes supplying a source of a nitridizing gas including gaseous NH3 to a glass article supported within a furnace assembly and heating the glass article. In some embodiments, the system includes a handle assembly configured to support the glass article within the furnace assembly and a gas supply conduit carried by the handle and configured to supply the nitridizing gas to the glass article. In some embodiments, a method of nitridizing a glass article includes supplying the nitridizing gas such that a residence time of the nitridizing gas at temperatures greater than 500° C. corresponds to a predetermined time period. In some embodiments, a method of nitridizing a glass article includes supplying the nitridizing gas such that the glass articles is exposed to the nitridizing gas within a contact time tc.

Abstract: An optical fiber can include a core comprising silica co-doped with nitrogen and chlorine and an outer cladding surrounding the core. In some aspects, the core can be characterized by an annealing temperature of less than or equal to about 1150° C. and/or the core can include a relative refractive index ?core in a range of from about 0.15% to about 0.45%.

Abstract: Multimode optical fibers are disclosed herein. In some embodiment disclosed herein, a multimode optical fiber having a bandwidth of greater than 2 GHz·km includes: a glass matrix having a front endface, a back endface, a length (L), a refractive index n20 and a central axis (AC); and a plurality of cores arranged within the glass matrix, wherein the plurality of cores run generally parallel to the central axis between the front and back endfaces and having respective refractive indices n50, wherein n50>n20, wherein the glass matrix serves as a common cladding for the plurality of cores so that each core and the common cladding define a waveguide, wherein each core is a single mode at an operating wavelength; and wherein any two cores have an center-to-center spacing s of 3 ?m to 20 ?m and a coupling coefficient of greater than 10 m?1 but less than 200 m?1.

Abstract: A multimode optical fiber having a core region. The core region includes silica, has an outer radius r1, and has a maximum relative refractive index of about 1.5% or less. Additionally, the multimode optical fiber is configured to have an effective bandwidth of about 4.7 GHz-Km or greater for an excited portion of the core region that has a diameter greater than 50 microns, the effective bandwidth being at a wavelength that is within a range of between about 800 and about 1370 nm.

Abstract: Small-radius coated optical fibers having large mode field diameter and low bending losses. The coated fiber may have an outer radius of 110 ?m or less, while providing a mode field diameter of 9.0 ?m or greater and a bending loss when wrapped about a 15 mm mandrel of 0.5 dB/km or less at wavelength of 1550 nm. The coated fiber may have a mode field diameter of 9.2 ?m or greater and may have a bending loss at 1550 nm of 0.25 dB/km or less when wrapped about a 20 mm mandrel or a bending loss at 1550 nm of 0.02 dB/km or less when wrapped about a 30 mm mandrel.

Abstract: A multicore optical fiber includes two or more cores, a common interior cladding surrounding the two or more cores, and a common exterior cladding surrounding the common interior cladding. The common exterior cladding has a lower relative refractive index than the common interior cladding and reduces tunneling losses from the cores. The reduced tunneling loss allows placement of cores closer to the edge of the fiber, thus providing multicore optical fibers having higher core count for a given fiber diameter. Separation between cores is controlled to minimize crosstalk.