Abstract: A method of manufacturing a preform, the method including positioning at least one glass tube in a glass outer cladding to form a preform precursor, the glass tube comprising a first open end and a second open end, forming a preform from the preform precursor, and thermally treating at least one of the preform precursor and the preform. The thermally treating including sealing the first open end and the second open end of the glass tube to form a closed tube and heating and/or cooling the glass tube to manipulate gas pressure within the closed glass tube.

Abstract: A method of manufacturing a hollow core optical fiber, the method including positioning at least one glass tube in a glass outer cladding to form a preform precursor, the glass tube comprising a first open end and a second open end, and forming a preform from the preform precursor. The method further including drawing the preform into a hollow core optical fiber and, while drawing the preform, thermally treating the preform to manipulate gas pressure within the glass tube by at least one of (i) heating at least a portion of the preform to increase gas pressure within the glass tube and (ii) cooling at least a portion of the preform to decrease gas pressure within the glass tube.

Abstract: A fiber coupler (135) for coupling a plurality of cores (160) of a multi-core optical fiber (105) to an integrated photonic device comprises a grating array comprising a plurality of polarization splitting gratings (180) arranged in a manner that corresponds to the plurality of cores (160) in the multi-core optical fiber (105). The fiber coupler (135) also comprises first and second mode converters (235, 240) extending from first and second sides of each of the plurality of polarization splitting gratings (180) to receive first and second polarization modes of the optical signal scattered by the polarization splitting grating (180). A plurality of waveguides (145-a, 145-b) extends from ends of each of the mode converters (235, 240) to guide a single polarization mode of one of the optical signals.

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 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 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 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: 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: An optical system, comprising: (i) multiple input optical fibers; (ii) an optical mode multiplexer/demultiplexer coupled to said input optical fibers with, said optical mode multiplexer/demultiplexer comprising a plurality of metamaterial structures having length and forming at least one stage of metamaterials, the at least one stage of metamaterials is being situated on a surface of the optical mode multiplexer/demultiplexer facing the input optical fibers, and the at least one stage of metamaterials is oriented at angles between 60 and 120 degrees relative to the axis of the input fibers; and the metasurfaces are structured to receive a first optical signal having a first mode from at least one of said multiple input optical fibers and convert the first mode to a different mode.

Abstract: Systems, devices, and techniques for performing wavelength division multiplexing or demultiplexing using one or more metamaterials in an optical communications systems are described. An optical device may be configured to shift one or more phase profiles of an optical signal using one or more stages of metamaterials to multiplex or demultiplex wavelengths of optical signals. The optical device may be an example of a stacked design with two or more stages of metamaterials stacked on top of one another. The optical device may be an example of a folded design that reflects optical signals between different stages of metamaterials.

Abstract: Systems, devices, and techniques for performing wavelength division multiplexing or demultiplexing using one or more metamaterials in an optical communications systems are described. An optical device may be configured to shift one or more phase profiles of an optical signal using one or more stages of metamaterials to multiplex or demultiplex wavelengths of optical signals. The optical device may be an example of a stacked design with two or more stages of metamaterials stacked on top of one another. The optical device may be an example of a folded design that reflects optical signals between different stages of metamaterials.

Abstract: Bend resistant multimode optical fibers are disclosed herein. Multimode optical fibers disclosed herein comprise a core region having a radius greater than 30 microns and a cladding region surrounding and directly adjacent to the core region, the cladding region comprising a depressed-index annular portion comprising a depressed relative refractive index. The fiber has a total outer diameter of less than 120 microns, and exhibits an overfilled bandwidth at 850 nm greater than 500 MHz-km.

Abstract: An optical fiber adapted to carry optical power for powering an electrical device and also optionally adapted to carry optical data for signal processing. The optical fiber capable of carrying both optical data and optical power includes a central data waveguide region that carries data light and an annular power waveguide region concentrically surrounding the data waveguide region and adapted to carry relatively large amounts of optical power. A first annular isolation region between the data and power waveguide regions and that includes microstructures serves to optically isolate the waveguide regions. An outer annular isolation region serves to confine power light to the power waveguide region and contributes to the bend-resistance of the optical fiber. An optical power and optical data distribution system that utilizes the optical fiber is also described.