Optical components and optical connectors for optical communication are disclosed. In one embodiment, an optical component includes a substrate having a lens surface, a fiber coupling surface, and an array of lenses at the lens surface. The optical component further includes an array of optical fibers bonded to the fiber coupling surface such that the array of optical fibers is aligned with the array of lenses in a plane defined by the fiber coupling surface.

A fiber optic directional sensor has a substantially hemispherical dome surface and a substantially flat surface. The sensor is formed from a plurality of optical fibers fused to one another, and each optical fiber extends from the dome surface to the flat surface. One end of each optical fiber is substantially perpendicular to the sensor's dome surface, and the opposite end of the fiber is substantially perpendicular to the sensor's flat surface such that an end face of the fiber is substantially tangent to the dome surface, and another end face of the fiber is substantially tangent to the flat surface. The sensor further includes an optical element which expands the field of view of the sensor and chromatically controls the incoming light. Using the sensor, light from projectiles, such as missiles, bullets, and other weaponry, can be detected, and the locations of the projectiles can be determined.

An optical fiber connection is provided that includes a first optical fiber defining a first exterior surface and a first effective area. The first fiber defines a first tapered region tapering from a first nominal fiber diameter to a first tapered diameter. A second optical fiber has a second exterior surface and a second effective area less than the first effective area. The second fiber defines a second tapered region tapering from a second nominal fiber diameter to a second tapered diameter and a fiber splice optically coupling the first tapered region of the first fiber to the second tapered region of the second fiber. The first and second tapered regions taper such that the first and second exterior surfaces have a variance from a Gaussian function of less than 25% of the Gaussian function at each point along the first and second exterior surfaces.

A wide angle illumination system and method. The wide angle illumination system is efficient in facilitating wide angle illumination of interior surfaces during vitreoretinal surgery. An optical fiber terminates in a convex semi-spherical end. A light source transmits a light beam through the optical fiber toward the convex semi-spherical end. An optical element has a flat, straight or planar end that is opposite to and adjoins a convex semi-spherical end which is adjacent to and which faces the convex semi-spherical end of the optical fiber. The light source transmits a light beam through the optical fiber convex semi-spherical end to the semi-spherical end of the optical element after which the convex semi-spherical end of the optical element transmits and diverges the light beam through the flat planar end into the interior of a surgical surface.

Lengths of an optical fiber may be broken apart from one another while a cross-sectional region of the optical fiber is in a state of multi-axial compressive stress, and the multi-axial compressive stress extends across the optical fiber. The breaking can include propagating a crack across the optical fiber. The crack can be positioned in sufficiently close proximity to the cross-sectional region so that the multi-axial compressive stress restricts the crack from penetrating the cross-sectional region. At least a portion of the optical fiber may be in tension during the breaking.

Provided is an optical coupler configured to cause an NA of light, which exits a taper fiber, to be smaller as compared with a conventional optical coupler. A taper fiber has a high refractive index part which is provided inside a core of the taper fiber and which has a refractive index smaller than a refractive index n.sub.core of the core. An exit end surface of each GI fiber is bonded to an entrance end surface of the taper fiber so that at least a part of the exit end surface of the each GI fiber overlaps with a section of the high refractive index part. A relative refractive index difference of the taper fiber is smaller than 0.076%.

A method for manufacturing an optical fiber, the method including: a stripping step of partially stripping a coating layer of the optical fiber; a splicing step of fusion-splicing an exposed end surface of a glass fiber; and a recoating step of recoating a protective resin covering a stripped portion of the coating layer and an exposed portion of the glass fiber, in which the stripping step is a step of irradiating the coating layer with a laser light to strip the coating layer.

An optical combiner 3 includes a plurality of incoming optical fibers 10, an outgoing optical fiber 20, and a plurality of bridge fibers 60, 50 provided between the plurality of incoming optical fibers 10 and the outgoing optical fiber 20, the plurality of bridge fibers 60, 50 being optically coupled to each other. In the bridge fibers 60, 50, a ratio of the outer diameter of a core 61, 51 to the outer diameter of a cladding 62, 52 is smaller in a bridge fiber located more apart from the incoming optical fiber 10.

A drawn glass element for producing glass optical waveguides is provided. The element has two first length portions with a first cross-sectional area and which define the two ends of the glass element; a second, intermediate length portion between the two first length portions, which has a second cross-sectional area smaller than the first cross-sectional area; a first transition portion between the intermediate length portion and one of the first length portions; and a second transition portion between the intermediate length portion and another of the first length portions. The first and second transition portions have a cross-sectional area that steadily changes and merges from the first cross-sectional area into the second cross-sectional area.

A reinforcing sleeve is a member for collectively reinforcing spliced portions of a plurality of optical fiber core wires disposed side by side. The reinforcing member includes a heat-shrinkable tube, a heat-meltable member, a tension member, and so on. The heat shrinkable tube is a cylindrical member having an approximately circular cross section. The heat-meltable member, which is a first heat-meltable member, is in a cylindrical shape having an approximately circular or elliptical cross section. The tension member is a rod-shaped member. The tension member and the heat-meltable member are inserted into the heat-shrinkable member. A thick portion is provided at a substantially center portion of a width direction of the heat-meltable member. Thus, on a cross section perpendicular to a longitudinal direction of the heat-meltable member, an amount of the heat-meltable member at proximity of the center portion of the width direction of the heat-meltable member is greater than an amount of the heat-meltable member at proximity of the end portions of the width direction of the heat-meltable member. This forms a flow of the heat-meltable member from the center portion toward the end portions in the width direction at the time of melting the heat-meltable member.