The disclosed embodiments generally relate to extruding multiple layers of micro- to nano-polymer layers in a tubular shape. In particular, the aspects of the disclosed embodiments are directed to a method for producing a Bragg reflector comprising co-extrusion of micro- to nano-polymer layers in a tubular shape.

A low latency free-space optical data communication channel has at least two opposing parabolic mirrors for transmitting an optical communication signal in the form of a parallel beam across a free-space channel. The input and output of the collimators are multicore optical fibers. Multiple cores of the multicore optical fibers are positioned at the focal points of the at least two opposing parabolic mirrors and the at least two opposing parabolic mirrors image the optical communications signal in each core of the multiple cores of the multicore fibers into corresponding cores of opposing multicore fibers forming at least one optical communication channel.

The rolled photonic fibers presents two codependent, technologically exploitable features for light and color manipulation: regularity on the nanoscale that is superposed with microscale cylindrical symmetry, resulting in wavelength selective scattering of light in a wide range of directions. The bio-inspired photonic fibers combine the spectral filtering capabilities and color brilliance of a planar Bragg stack compounded with a large angular scattering range introduced by the microscale curvature, which also decreases the strong directional chromaticity variation usually associated with flat multilayer reflectors. Transparent and elastic synthetic materials equip the multilayer interference fibers with high reflectance that is dynamically tuned by longitudinal mechanical strain. A two-fold elongation of the elastic fibers results in a shift of reflection peak center wavelength of over 200 nm.

A device for coupling optical fibers, includes a first coupling-inhibited hollow-core optical fiber comprising a first microstructured cladding comprising a plurality of first confining tubular features distributed in a ring and encircling, at least partially, a first core so as to confine at least radiation at a wavelength ?op to the first core, a second coupling-inhibited hollow-core optical fiber comprising a second microstructured cladding comprising a plurality of second confining tubular features distributed in a ring and encircling, at least partially, a second core so as to confine the light radiation to the second core, a coupling element arranged between the first and second cores, the coupling element comprising at least one coupling tubular feature comprised at least partially in the first microstructured cladding and/or the second microstructured cladding and having a wall thickness tcp called the coupling thickness and a material index ncp called the coupling index, an arrangement of the coupling element, the coupling thickness tcp and the coupling index ncp being configured so as to create a leakage channel at the wavelength ?op allowing the radiation guided by the first optical fiber to be coupled to the second optical fiber and/or the radiation guided by the second optical fiber to be coupled to the first optical fiber.

A hollow core fiber (HCF) link is characterized by structural properties selected to support and sustain light propagation in a fundamental mode and in at least one higher-order mode. Connected to a proximal end of the HCF link, there is a mode coupler configured to couple a data signal into the fundamental mode and to couple an obfuscating signal into the at least one higher-order mode for simultaneous propagation of the data signal and the obfuscating signal on the HCF link, where the obfuscating signal substantially overlaps the data signal in spectral content. At a distal end of the HCF link, there is a mode splitter configured to split a first optical signal detected in the fundamental mode from a second optical signal detected in the at least one higher-order mode.

The disclosed embodiments generally relate to extruding multiple layers of micro- to nano-polymer layers in a tubular shape. In particular, the aspects of the disclosed embodiments are directed to a method for producing a Bragg reflector comprising co-extrusion of micro- to nano-polymer layers in a tubular shape.

The present disclosure provides systems and methods for optically coupling a solid-core fiber (SCF) with a hollow-core fiber (HCF). Briefly described, one embodiment of the system comprises a graded-index (GRIN) fiber and a hollow fiber (HF) that optically couple the SCF with the HCF. The combination of the GRIN with the HF permits mode matching between the SCF and the HCF, while concurrently increasing return loss from the HCF to the SCF.

A method for the detection of a gas flowing from a location in a structure is described. A hollow-core optical fiber is placed in a position adjacent the structure. The fiber includes a sound-conductive cladding layer; and further includes at least one aperture extending into its cross-sectional diameter. A beam of pulsed, optical is transmitted into the fiber with a tunable laser. The optical energy is characterized by a wavelength that can be absorbed by the gas that flows into the fiber through the aperture. This causes a temperature fluctuation in the region of gas absorption, which in turn generates an acoustic wave in the absorption region. The acoustic wave travels through the cladding layer, and can be detected with a microphone, so as to provide the location of gas flow, based on the recorded position and movement of the acoustic wave. A related system is also described.

A patch cord for transmitting between a single mode fiber (SMF) and a multi-mode fiber (MMFs) has a MMF, SMF, and a photonic crystal fiber (PCF) with a hollow core placed between the SMF and MMF. A mode field diameter (MFD) of the PCF hollow core section is in the range of 16 to 19 microns, the length of the PCF is between 1 cm to 10 cm, the MMF has 502 microns core diameter, the SMF has a 6-9 microns core diameter, and the coupling between the PCF mode to the MMF fundamental mode is maximized.

A method of making chalcogenide based polymeric materials and converting those materials into optical fiber preforms and polymeric optical fibers. The preforms and fibers comprise chalcogenide elements and crosslinking moieties. These fibers can be used as optical waveguides at infrared wavelengths where other polymer fibers do not operate. The optical waveguides are ideally suitable for applications requiring the transmission of low-power infrared light, but may also be useful for transmitting high-power light at visible or infrared wavelengths.