A terminus for a fiber optic cable includes a ferrule. In one embodiment, an optical fiber of the cable passes through a central bore of the ferrule and is attached to a lens seated in a conical or cylindrical seat formed in an end surface of the ferrule by an epoxy. In a second embodiment, an optical fiber of the cable passes through the central bore of the ferrule. Next, a cap sleeve with a lens therein is slid over and attached to the ferrule such that the lens abuts or is attached to the optical fiber. In either embodiment, an inspection slot may optionally be formed in the ferrule and/or the cap sleeve to allow a technician to inspect the state of the attachment and/or abutment and/or spacing of the optical fiber and the lens.

An optical connection structure includes a MCF, a first ferrule, a plurality of optical fibers, and a second ferrule. The MCF includes first cores and a first cladding. The first ferrule has a first inner hole and a first ferrule end surface. Each optical fiber optically connected to the MCF includes a second core and a second cladding. The second ferrule has a second inner hole housing tip parts of the optical fibers, and a second ferrule end surface. The second ferrule fixes the tip parts of the optical fibers in the second inner hole by an adhesive. The adhesive is packed in the second inner hole such that a surface of the adhesive is recessed from the second ferrule end surface into the second inner hole. A refractive-index matching material is applied in a space sealed by the first ferrule end surface and the second ferrule end surface.

A protective assembly method using a transparent layer within the fiber interconnect system aids in optical coupling by preventing an air gap from forming between the fiber cores within a connector. A fiber protection device made of a thin transparent film, which includes an adhesive layer, is applied over the fiber end-faces at the connector interface, the film having characteristics which allows it to conform to the fiber end and minimize coupling loss between fibers. According to one aspect, the film is part of a cartridge that provides structural support for the film to facilitate application of the fiber protection device. The film may be divided by perforate patterns that define one or more fiber protection devices formed by the film. The assembly method can include usage of an applicator base plate upon which the cartridge is mounted. According to another aspect, the film may be part of a single-use disposable pod for application of a single fiber protection device.

An optical system and method for connecting two optical fibers is described in the present disclosure. An example optical system includes a first optical fiber embedded in an embedding material, the first optical fiber comprising side walls extending in a longitudinal direction in contact with the embedding material, a second, external, optical fiber, and a self-written waveguide in optical contact with the first and second optical fibers. Only a cross section perpendicular to the side walls of the first optical fiber is outside the embedding material, in contact with the self-written waveguide.

A ferrule structure includes: a ferrule body including a guide hole that accepts insertion of a guide pin, and a fiber hole that accepts insertion of an optical fiber and that is disposed in an opening surface of the ferrule body; and a lens plate including a guide hole that accepts insertion of the guide pin, a lens part, and an abutment surface that abuts an endface of the optical fiber. A recess is disposed in at least one of the ferrule body and the lens plate. A matching material filling gap, that is to be filled with a refractive index matching material, is formed with the recess, between the opening surface of the ferrule body and the abutment surface of the lens plate.

Aspects and techniques of the present disclosure relates generally to incorporating an index matching gel within a HMFOC such that as the HMFOC is mated, fiber tips protruding from multi-fiber ferrules of the HMFOC pass through the indexing matching gel to remove contaminates therefrom. The present disclosure also relates to a method of removing contaminates from optical fibers upon mating a hardened multi-fiber optical connector (HMFOC) with another HMFOC.

An air-gap HCF connector termination method and connector assembly for factory and field connector assembly termination for patch cables and trunk cables made from HCF, where in multitude of mechanisms can facilitate air-gap between the first and second HCF fiber end-faces, comprising preparing the HCF end-faces using appropriate cleaving methods including mechanical, ultrasonic and laser cleaving, such that the air-gap separation between first and second HCF's can be anywhere between 0.5-100 microns, where reflection at the connector interface is low with RL>35 dB, due to HCF propagation mode effective index matching with index of air.

A tapered waveguide is optically connected to an end surface of an optical fiber bundle part, and has a tapered part that changes in outside diameter in a tapered shape. The fiber bundle part is optically connected to the end surface of the large-diameter side of the waveguide. The entire waveguide has a substantially uniform index of refraction. A delivery fiber is optically connected to the end surface on the small-diameter side of the waveguide. As with the fiber bundle part the delivery fiber passes through a hole in a capillary and is affixed. The capillaries are each affixed to a retaining member such that the fiber bundle part, the waveguide, and the delivery fiber are disposed on the same axis and optically connected. The waveguide is retained in a state floating from the retaining member, and the outside surface of the waveguide is not in contact with the retaining member.

A method of manufacturing an optical connector according to the invention includes: holding a first optical fiber by a pair of holding members at a position apart from an end face of a second end and through both sides thereof in a radial direction, the first optical fiber being provided with a solid refractive index-matching material layer, the refractive index-matching material layer being formed on the end face of the second end on an opposite side of an end face of a first end exposed to a front end of a ferrule; and inserting the first optical fiber into a fiber hole of the ferrule through the first end.

An optical connector includes a ferrule, a first optical fiber retained in the ferrule, a clamp section including an insertion section where a second optical fiber is inserted, a solid index-matching material disposed on an end face of the first optical fiber on an insertion section side, and a projecting portion on the end face of the first optical fiber and that projects more toward the insertion section side than a central region of the end face. The clamp section centers and fixes the first optical fiber and the second optical fiber.