Abstract: A high fiber count, ferrule-terminated optical fiber cable assembly includes a high density two-dimensional array of optical fibers extending through a single aperture of a ferrule, with the optical fibers within the ferrule aperture each having a core, a cladding layer, and a hard coating layer (e.g., having an elastic modulus greater than 100 MPa). Hard coated optical fibers are arranged very close to (e.g., within two microns of, or in contact with) one another, with a substantially constant fiber pitch within the ferrule. A fusion splice region may be provided between ferrule terminated hard-coated optical fibers and conventional optical fibers lacking a hard coating. High optical fiber density and compact ferrule size permits a significant reduction in connector width, enabling a numerical reduction or elimination of staggered lengths of cable portions for coupling ultra-high density optical fiber cables.

Abstract: In some embodiments, a method for processing an optical fiber includes: drawing an optical fiber through a draw furnace, conveying the optical fiber through a flame reheating device downstream from the draw furnace, wherein the flame reheating device comprises one or more burners each comprising: a body having a top surface and an opposing bottom surface, an opening within the body extending from the top surface through the body to the bottom surface, wherein the optical fiber passes through the opening, and one or more gas outlets within the body; and igniting a flammable gas provided by the one or more gas outlets to form a flame encircling the optical fiber passing through the opening, wherein the flame heats the optical fiber by at least 100 degrees Celsius at a heating rate exceeding 10,000 degrees Celsius/second.

Abstract: The present disclosure relates to laser treatment of an optical fiber to secure the optical fiber within a ferrule bore. In particular, the laser treatment modifies the physical structure of the optical fiber to aid in securing the optical fiber within the ferrule bore and to correct core-to-ferrule eccentricity errors.

Abstract: A silica-based substrate includes a glass phase and a dispersed phase having carbon, such that the silica-based substrate has a thickness of at least 10 gm. Also disclosed is a method of forming a silica-based substrate, the method including contacting a porous silica soot preform with an organic solution having at least one hydrocarbon precursor to form a doped silica soot preform and heating the doped silica soot preform in an inert atmosphere to form the silica-based substrate.

Abstract: In one embodiment, a multicore optical fiber connector adapter includes at least one multicore optical fiber stub that includes a plurality of optical cores, each optical core having an inner core and an outer core, a fiber coupling section having a first diameter, wherein the cores have a first pitch at the fiber coupling section, a multicore fiber coupling section having a second diameter that is less than the first diameter, wherein the cores have a second pitch at the multicore fiber coupling section that is less than the first pitch, and a taper section between the fiber coupling section and the multicore fiber coupling section. The multicore optical fiber connector adapter further includes at least one multicore ferrule comprising a passageway, a multicore connector, a plurality of optical fibers, and a multi-fiber ferrule.

Abstract: A multicore optical fiber is provided including a first core region having a first refractive index profile, a second core region having a second refractive index profile, wherein the first core region is separated from the second core region by a separation distance in a range of 20-50 ?m, and an outer cladding surrounding the first and second core regions, wherein the first core region exhibits a first effective index and a first group index and the second core region exhibits a second effective index and a second group index, and the first and second effective indices are substantially different to suppress crosstalk and the first and second group indices are substantially the same to achieve a substantially similar group velocity.

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: The present disclosure is directed to various embodiments of methods for making an optical fiber. The methods may include drawing an optical fiber from a hollow-core preform. The hollow-core preform may include an annular support structure with an inner surface defining an interior cavity. The interior cavity may include a tube in direct contact with the inner surface of the annular support structure. The tube may include a wall defining an internal opening, the internal opening having a sealed end. The drawing may include regulating a pressure of the internal cavity to a predetermined pressure.

Abstract: Disclosed herein is a fiber optic system including at least one fiber optic cable assembly having a multimode optical fiber for communication of an optical data signal at an operating wavelength and a devices having a single-mode fiber stub with a mode field diameter within 20% of the mode field diameter of the fundamental mode of the multimode optical fiber at the operating wavelength. The single-mode fiber stub is secured to a ferrule, and a center of a core of the single-mode fiber stub is within 0.5 ?m of a center of the ferrule. An end of the single-mode fiber stub that extends to or beyond the back end of the ferrule and forms an optical connection with the multimode optical fiber where the center of the single-mode fiber stub is within 2 ?m of a center of the multimode optical fiber.

Abstract: A hollow-core optical fiber may include a hollow-core extending along a central longitudinal axis of the hollow-core optical fiber; a substrate; a first cladding positioned between the central longitudinal axis and an inner surface of the substrate, the first cladding surrounding the central longitudinal axis of the hollow-core optical fiber and having a Bragg structure configured to provide a photonic bandgap operable to confine an optical signal with a wavelength ? propagating in the hollow-core of the hollow-core optical fiber; and a second cladding positioned between the central longitudinal axis of the hollow-core optical fiber and the inner surface of the substrate, the second cladding surrounding the central longitudinal axis of the hollow-core optical fiber and including a plurality of cladding elements configured to provide an anti-resonant effect at the wavelength ?, the anti-resonant effect operable to confine the optical signal at the wavelength ? in the hollow-core.

Abstract: A method for producing a hollow-core preform may include rolling a glass sheet to form a rolled-glass structure; and attaching one or more of the rolled-glass structures to an inner surface of an annular support structure to form a hollow-core preform, wherein the inner surface of the annular support structure defines an interior cavity and the one or more of the rolled-glass structures are positioned within the interior cavity. The hollow-core preform may be drawn into a hollow-core optical fiber.

Abstract: A hollow-core optical fiber may include a hollow core extending along a central longitudinal axis of the fiber; a substrate; a plurality of first cladding elements spaced apart from each other and positioned between the hollow core and the substrate, each of the first cladding elements extending in a direction parallel to the central longitudinal axis of the fiber, each of the first cladding elements including a first capillary; and a plurality of second cladding elements spaced apart from each other and positioned between the hollow core and the substrate, each of the second cladding elements extending in a direction parallel to the central longitudinal axis of the fiber, each of the second cladding elements including a second capillary. Each of the first cladding elements directly contacts the inner surface of the substrate, and none of the second cladding elements directly contacts the inner surface of the substrate.

Abstract: A hollow-core optical fiber may include a hollow core extending along a central longitudinal axis of the fiber; a substrate, the substrate having a tubular shape and an inner surface surrounding the central longitudinal axis of the fiber; and a plurality of cladding elements positioned between the hollow core and the substrate, each of the cladding elements extending in a direction parallel to the central longitudinal axis of the fiber. Each of the cladding elements includes a primary capillary, the primary capillary directly contacting the inner surface of the substrate and having an inner surface defining a cavity, and a plurality of nested capillaries positioned within the cavity, each of the nested capillaries directly contacting the inner surface of the primary capillary.

Abstract: A hollow-core optical fiber may include a substrate having a tubular shape and an inner surface surrounding a central longitudinal axis of the hollow-core optical fiber; a hollow core extending through the substrate along the central longitudinal axis of the hollow-core optical fiber; and a plurality of cladding elements positioned between the central longitudinal axis of the hollow-core optical fiber and the substrate. Each of the plurality of cladding elements may extend in a direction parallel to the central longitudinal axis of the hollow-core optical fiber. Each of the plurality of cladding elements may include a wound glass sheet configured as a spiral, and each of the plurality of cladding elements may contact an interior surface of the substrate.

Abstract: A rollable optical fiber ribbon utilizing low attenuation, bend insensitive fibers and cables incorporating such rollable ribbons are provided. The optical fibers are supported by a ribbon body, and the ribbon body is formed from a flexible material such that the optical fibers are reversibly movable from an unrolled position to a rolled position. The optical fibers have a large mode filed diameter, such as ?9 microns at 1310 nm facilitating low attenuation splicing/connectorization. The optical fibers are also highly bend insensitive, such as having a macrobend loss of ?0.5 dB/turn at 1550 nm for a mandrel diameter of 15 mm.

Abstract: An apparatus comprises a fiber input, the fiber input comprising a plurality of input fiber cores receiving a plurality of input optical signals. The apparatus also comprises an optical signal manipulation device that is one of a fiber mode shuffler, a fiber coupler, a power splitter, or a 90-degree optical hybrid. The optical signal manipulation device comprises an input aperture held in spaced relation to the fiber input, an output aperture, and a plurality of metasurfaces that manipulate phase profiles of the plurality optical signals to generate a plurality of output optical signals having a different spatial arrangement than the input optical signal. A fiber output is held in spaced relation to the output aperture such that fiber cores of the fiber output receive the plurality of output optical signals.

Abstract: A few mode optical fiber that includes a core and a cladding surrounding the core, the cladding comprising at least one stress member. The core and the cladding support the propagation and transmission of at least LP01, LP11a, and LP11b modes at one or more wavelengths. Furthermore, the LP01, LP11a, and LP11b modes each have a birefringence of about 5.7×10?6 or less at 1310 nm. And an effective index difference between the LP11a and LP11b modes is about 3.0×10?5 or greater.

Abstract: The disclosure provides optical fibers that exhibit low macrobend loss at 1550 nm at bend diameters between 10 mm and 40 mm. The relative refractive index profile of the fibers includes a trench cladding region with small depth, large width and a trench volume configured to minimize macrobend loss at large and small bend diameters. The optical fiber includes an outer cladding region that surrounds and is directly adjacent to the trench cladding region and an optional offset cladding region between the trench cladding region and the core region. In some embodiments, the trench cladding region has a relative refractive index that decreases monotonically from the inner radius to the outer radius. The monotonic decrease in relative refractive index may have a constant slope. The low macrobend loss at large and small diameters makes the optical fibers well suited for space-constrained deployment environments, such as data centers.

Abstract: The optical fiber disclosed has a glass fiber including a core and a cladding. The core comprises silica glass doped with chlorine and having an outer radius r1 between 3.0 microns and 10.0 microns. The cladding has an outer radius r4 not less than 50.0 microns. A primary coating surrounding the cladding has a thickness (r5?r4) between 5.0 microns and 20.0 microns, and an in situ modulus less than 0.30 MPa. A secondary coating surrounding the primary coating has a thickness (r6?r5) between 8.0 microns and 30.0 microns, a Young's modulus greater than 1500 MPa, and a normalized puncture load greater than 3.6×10?3 g/micron 2. The optical fiber has a 22-meter cable cutoff wavelength less than 1530 nm, an attenuation at 1550 nm of less than 0.17 dB/km, and a bending loss at 1550 nm of less than 3.0 dB/turn.

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.