A multi-core fiber includes: a plurality of core portions each including a central core portion, an intermediate layer formed on an outer periphery of the central core portion, and a trench layer formed on an outer periphery of the intermediate layer; and a cladding portion formed on an outer periphery of the plurality of core portions, wherein in each of the plurality of core portions, Δ1>Δ2>Δ3 and 0%>Δ3>−0.3% are satisfied, where Δ1 is an average maximum relative refractive-index difference of the central core portion, Δ2 is an average relative refractive-index difference of the intermediate layer, and Δ3 is an average relative refractive-index difference of the trench layer, with respect to the cladding portion.

Optical communication system communicates between an array of originating tiles and an array of terminating tiles. Each array is associated with a lenslet array, such as a two-layer array. Each originating tile has an array and each terminating tile has an array of transceivers. Each tile is associated with a common lenslet or lenslet pair. A beamlet from a representative originating transceiver passes through the lenslet pair adjacent to its tile via an originating Fourier transform element, collimating optics, and a terminating Fourier transform element. The beam then passes through the lenslet pair adjacent to the tile containing the terminating transceiver associated with the representative originating transceiver, and is focused onto that receiver by that lenslet pair. Originating and/or terminating arrays of multicore fibers may be used between the originating transceivers and the originating Fourier transform element and/or between the terminating Fourier transform element and the terminating transceivers.

A method of processing by controlling one or more beam characteristics of an optical beam may include: launching the optical beam into a first length of fiber having a first refractive-index profile (RIP); coupling the optical beam from the first length of fiber into a second length of fiber having a second RIP and one or more confinement regions; modifying the one or more beam characteristics of the optical beam in the first length of fiber, in the second length of fiber, or in the first and second lengths of fiber; confining the modified one or more beam characteristics of the optical beam within the one or more confinement regions of the second length of fiber; and/or generating an output beam, having the modified one or more beam characteristics of the optical beam, from the second length of fiber. The first RIP may differ from the second RIP.

An optical fiber module is disclosed. The optical fiber module includes a first optical fiber as an MCF, a plurality of second optical fibers as MCFs, a first unit, and a second unit. The first unit has an hole holding the first optical fiber and a plurality of holes respectively holding the second optical fibers. These holes are independent of each other. Each optical fiber has a first part and a second part. An outer surface of a cladding of the first part is coated with a resin. An outer surface of a cladding of the second part is exposed from the resin. The first unit holds the first part. The second unit holds the second part. A boundary between the first part and the second part is positioned in a space between the first unit and the second unit.

The present disclosure provides devices, systems, circuits, and effective methods for advanced optical applications using plasmonics and ENZ materials. The disclosure provides for enhancement of the optical tunability of phase and amplitude of propagating plasmons, nonlinear-optical effects, and resonant network in optical fiber tip nanocircuits and integrates the tunable plasmonic and ENZ effects for in-fiber applications to provide optical fiber with high operating speed and low power consumption. The invention yields efficient coupling of a plasmonic functional nanocircuit on the facet of an optical fiber core. The invention also can use gate-tunable ENZ materials to electrically and nonlinear optically tune the plasmonic nanocircuits for advanced light manipulation. The invention efficiently integrates and manipulates the voltage-tuned ENZ resonance for phase and amplitude modulation in optical fiber nanocircuits.

An optical fiber (F2) having a length defining a longitudinal direction is disclosed. The optical fiber (F2) has at least two fiber cores (C21, C22) extending along the length of the optical fiber (F2), and an optical coupling member (OCM2) is arranged at a proximal optical fiber end of the optical fiber (F2). The coupling member (OCM2) has a first distal end face (OF2) optically connected to the proximal optical fiber end, and a proximal second end face (IF2) spaced apart from the first distal end face (OF2) in the longitudinal direction of the optical fiber (F2), the optical coupling member (OCM2) being configured to couple light into each of the fiber cores (C21, C22, C23).

A cable comprising: a plurality of optical fiber cores; and one or more optical fiber core wires including one or more of the optical fiber cores. Further, at least one of the optical fiber core wire is fixed at a plurality of positions in a longitudinal direction of the cable so as to achieve substantially no displacement in a cable radial direction, at least a pair of the optical fiber core wires are fixed in a plane perpendicular to the longitudinal direction of the cable so as to achieve substantially no displacement relative to each other, and sensing of a strain profile in the longitudinal direction of at least the pair of the optical fiber core wires leads to achievement of sensing of a shape of the cable in the longitudinal direction.

A photon detection device, configured to couple to a multicore optical fibre, the device comprising a plurality of detection regions, each detection region being arranged to align with just a single core of the multicore optical fibre when the device is coupled to the multicore optical fibre.

An optical device that includes a multicore optical fiber having at least two cores. An alignment feature is attached at the first end of the first multicore optical fiber. The device also includes a substrate having at least two waveguides, each waveguide comprising a redirecting feature. A fiber holder is located on the substrate to hold the multicore fiber in a correct axially rotational orientation using the alignment feature, so that light couples between the cores of the multicore fiber and respective waveguides in the substrate.

An optical guidewire system employs an optical guidewire (10), an optical guidewire controller (12), a guide interface (13) and an optical connector (15). The optical guidewire (10) is for advancing a catheter (20) to a target region relative to a distal end of the optical guidewire (10), wherein the optical guidewire (10) includes one or more guidewire fiber cores (11) for generating an encoded optical signal (16) indicative of a shape of the optical guidewire (10). The optical guidewire controller (12) is responsive to the encoded optical signal (16) for reconstructing the shape of the optical guidewire (10). The guidewire interface (13) includes one or more interface fiber core(s) (14) optically coupled to the optical guidewire controller (12). The optical connector (15) facilitates a connection, disconnection and reconnection of the optical guidewire (10) to the guidewire interface (13) that enables a backloading the catheter (20) on the optical guidewire (10).