Improved optical fiber coupling reliability is realized by improving structures and materials used at the fiber joint. When ceramic ferrules are used at the fiber joint, the penetration of a UV-cured optical adhesive between the ceramic ferrules and the fiber ends is avoided or prevented, while an anti-reflective coating, an uncured optical adhesive, or a refractive index matching gel may be applied between the ceramic ferrules. When glass ferrules are used at the fiber joint, the UV-cured optical adhesive may be applied and fully cured between the glass ferrules and the fiber ends.

A fiber alignment device is provided that includes a curable refractive index-matching gel that exhibits self-cleaning and self-healing characteristics upon multiple cycles of insertion and removal of an optical fiber.

An optical-fiber-attached ferrule of the invention includes: an optical fiber; and a ferrule that holds an end portion of the optical fiber, where the ferrule includes a ferrule end surface, a fiber hole to insert the optical fiber, an adhesive-filling section that includes an opening surface of the optical fiber hole and an opposed surface opposed to the opening surface, and a light transmitting part that transmits an optical signal between the ferrule end surface and the opposed surface, and an end surface of the optical fiber is disposed close to the opposed surface in the adhesive-filling section The adhesive-filling section is filled with an optical adhesive with Shore hardness D of equal to or less than 50.

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.

A low-reflection fiber-optic connector. The fiber-optic connector includes a ferrule that includes a fiber passage and an optical fiber traversing the fiber passage. The optical fiber includes a polished fiber end that is substantially flush with a ferrule end face. The ferrule end face, in an area surrounding the polished fiber end, is modified to reduce an optical reflectivity.

A ferrule that holds an end part of an optical fiber includes a fiber hole into which the optical fiber is inserted and an upper wall part and a lower wall part that define a hollow adhesive filling part, where the lower wall part faces the upper wall part. The adhesive filling part is filled with an adhesive applied between the optical fiber inserted in the fiber hole and an inner wall surface of the adhesive filling part. The upper wall part has an upper opening through which the adhesive passes into the adhesive filling part, and the lower wall part has a lower opening that ventilates the adhesive filling part to outside of the ferrule.

An optical ferrule includes at least one light affecting element configured to affect one or more characteristics of light from an optical waveguide as the light propagates in the optical ferrule, the light affecting element having an input surface. At least one receiving element receives and secures the optical waveguide to the ferrule so that an output surface of the waveguide is optically coupled to the input surface of the light affecting element. A waveguide stop limits movement of the waveguide toward the input surface of the light affecting element when the optical waveguide is installed in the receiving element. A space between the output surface of the optical waveguide and the input surface of the light affecting element is inaccessible to the optical waveguide when the optical waveguide is installed in the receiving element.

A fiber optic connector includes polymeric material arranged within a front end portion of at least one internal bore of a ferrule. At least a portion of the polymeric material extends from a terminal end of at least one optical fiber to at least a front end of the ferrule. A polymeric material end face serving as a conduit for transmitting optical signals to and/or from the at least one optical fiber. Waveguiding regions may be incorporated in polymeric material assemblies. Polymeric material may be printed, dispensed, or otherwise applied over the terminal end of the at least one optical fiber in the at least one internal bore, and subsequently cured. Polymeric material arranged over (e.g., in contact with) the terminal end of an optical fiber may reduce or eliminate the need for fiber end face polishing, and creates physical contact through an optical interface without exerting undue mechanical stresses on the optical fiber.

A method of preparing an optical connector located within a gap between a first optical assembly and a second optical assembly is provided. The optical connector includes a contrast layer having at least one cured bridge portion and at least one uncured portion formed from a first composition having a first refractive index (RI.sup.1). The method comprises applying a second composition having a second refractive index (RI.sup.2) on the contrast layer to form a second layer and mixing at least a portion of the second layer with the at least one uncured portion of the contrast layer to form at least one intermixed portion having a third refractive index (RI.sup.3), wherein R|.sup.1>R|.sup.3>RI.sup.2, and then curing the intermixed portion and optional second layer such that each one of the at least one cured bridge portions is surrounded by an intermixed portion and optional second layer.

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.