Abstract: A ferrule structure includes: a holding aperture that holds light guide members forming light guides; a recess that is recessed from a connection end surface with respect to a mating ferrule; a first lens array on a base surface that is a bottom surface of the recess; and a first groove that is recessed from the base surface and is on an outer side of the first lens array. The first lens array includes lenses that are aligned with the light guides.

Abstract: A cleaning tool for cleaning a plurality of optical connectors where the cleaning tool includes: an adhesive portion that is integrally formed with the cleaning tool and that contacts a plurality of connecting end faces of the optical connectors collectively. The plurality of optical connectors are inserted into and connected with one housing that is fitted with another housing. The adhesive portion is disposed on the other housing. The adhesive portion contacts the connecting end faces collectively by fitting the one housing with the other housing.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A cleaning tool that cleans an optical connector includes an adhesive body that contacts an optical signal region of the optical connector where an optical signal enters and is emitted from the optical connector. The adhesive body includes a protrusion that protrudes in a region—that contacts the optical signal region.

Abstract: A cleaning tool for cleaning a plurality of optical connectors where the cleaning tool includes: an adhesive portion that is integrally formed with the cleaning tool and that contacts a plurality of connecting end faces of the optical connectors collectively. The plurality of optical connectors are inserted into and connected with one housing that is fitted with another housing. The adhesive portion is disposed on the other housing. The adhesive portion contacts the connecting end faces collectively by fitting the one housing with the other housing.

Abstract: An optical loopback member attaches to a counterpart optical connector to face a plurality of optical fibers of the counterpart optical connector that includes a first input optical fiber, second input optical fiber, first output optical fiber, and second output optical fiber. The optical loopback member includes a first reflector including: a first output light reflection surface that reflects a first output light, outputted in a first direction, from the first output optical fiber; and a first input light reflection surface that reflects light reflected by the first output light reflection surface and directs the reflected light to the first input optical fiber arranged in a second direction with respect to the first output optical fiber. The second direction is perpendicular to the first direction.

Abstract: 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.