Space division multiplexers can include adapters between multicore fibers with different core patterns and/or add-drop multiplexers for multicore fibers.

An MCF according to one embodiment simultaneously achieves excellent economic rationality and high compatibility in short-distance optical transmission. The MCF includes a plurality of core portions, a common cladding, and a resin coating. Each of the core portions includes a core, an inner cladding, and a trench layer. At least four core portions arranged on a straight line have substantially the same relative refractive index difference between the core and the inner cladding. The refractive index profile of a first core portion and a second core portion adjacent to each other among the four core portions has a shape in which the refractive index of the inner cladding is offset with respect to the refractive index of the common cladding so that the magnitude relationship of the refractive index between the inner cladding and the common cladding is reversed.

An MCF according to one embodiment simultaneously achieves excellent economic rationality and high compatibility in short-distance optical transmission. The MCF includes a plurality of core portions, a common cladding, and a resin coating. Each of the core portions includes a core, an inner cladding, and a trench layer. At least four core portions arranged on a straight line have substantially the same relative refractive index difference between the core and the inner cladding. The refractive index profile of a first core portion and a second core portion adjacent to each other among the four core portions has a shape in which the refractive index of the inner cladding is offset with respect to the refractive index of the common cladding so that the magnitude relationship of the refractive index between the inner cladding and the common cladding is reversed.

Disclosed herein is a method for measuring temperature via distributed temperature sensing comprising transmitting light through a fiber optic cable; detecting backscattered light in the fiber optic cable, wherein the backscattered light comprises an anti-Stokes band and a Stokes band; calculating a ratio between an intensity of the anti-Stokes band and an intensity of the Stokes band; and using the calculated ratio to determine a temperature being sensed in the fiber optic cable; wherein the fiber optic cable comprises, from the center to the periphery; a central core having a refractive index that decreases progressively from a center of the central core to an edge of the core, wherein the refractive index follows an alpha profile; wherein a bandwidth-length product of the multimode optical fiber has a value greater than 2000 MHz-km at 1550 nm.

An embodiment apparatus comprises an optically transparent substrate having first and second surfaces; a piezoelectric membrane, arranged at the first surface, that oscillates in response to a light beam propagated through the substrate; at least one reflective facet facing the substrate and arranged at the piezoelectric membrane; and an optical element receiving the light beam at an input end and guiding the light beam towards an output end coupled to the second surface. The optical element incorporates a light focusing path focusing the light beam at a focal point at the piezoelectric membrane, and at least one light collimating path collimating the light beam onto the at least one reflective facet. The optical element guides light reflected from the at least one reflective facet to the input end, the reflected light indicating a position of the optical element with respect to the focal point.

An embodiment apparatus comprises an optically transparent substrate having first and second surfaces; a piezoelectric membrane, arranged at the first surface, that oscillates in response to a light beam propagated through the substrate; at least one reflective facet facing the substrate and arranged at the piezoelectric membrane; and an optical element receiving the light beam at an input end and guiding the light beam towards an output end coupled to the second surface. The optical element incorporates a light focusing path focusing the light beam at a focal point at the piezoelectric membrane, and at least one light collimating path collimating the light beam onto the at least one reflective facet. The optical element guides light reflected from the at least one reflective facet to the input end, the reflected light indicating a position of the optical element with respect to the focal point.

A method for manufacturing an optical fibre includes placing the powdery substance compactly in the fluorine doped tube to form a core section. The core section of the glass preform is defined along a longitudinal axis of the glass preform. In particular, the fluorine doped tube is sintered to solidify the powdery substance. Moreover, the glass preform is heated at high temperature to draw the optical fibre.

Disclosed is a polymeric waveguide for propagating light therein along width and length dimensions of the polymeric waveguide. The polymeric waveguide has a first curved surface on one side thereof and a second curved surface on an opposite second side thereof, and a refractive index spatially varying through a thickness thereof between the first curved surface and the second curved surface. The polymeric waveguide is curved in a cross-section comprising at least one of the width and length dimensions.

An in-fiber beam scanning system may comprise an input fiber to provide a beam, a feeding fiber comprising an imaging bundle with multiple cores embedded in a first cladding that is surrounded by a second cladding, and an in-fiber beam shifter that comprises a first multibend beam shifter coupled to the input fiber, a graded index fiber following the first multibend beam shifter, and a second multibend beam shifter following the graded index fiber and coupling into the feeding fiber. In some implementations, the first multibend beam shifter is actuated by a first amount and the second multibend beam shifter is actuated by a second amount to shift the beam in two dimensions and deliver the beam into one or more target cores in the imaging bundle.

An in-fiber beam scanning system may comprise an input fiber to provide a beam, a feeding fiber comprising an imaging bundle with multiple cores embedded in a first cladding that is surrounded by a second cladding, and an in-fiber beam shifter that comprises a first multibend beam shifter coupled to the input fiber, a graded index fiber following the first multibend beam shifter, and a second multibend beam shifter following the graded index fiber and coupling into the feeding fiber. In some implementations, the first multibend beam shifter is actuated by a first amount and the second multibend beam shifter is actuated by a second amount to shift the beam in two dimensions and deliver the beam into one or more target cores in the imaging bundle.