Systems, methods, and devices for a universal connector/adaptor to connect any of a multitude of different fiber optic cables (including any bare ferrule surface and/or end connector thereof) with any of a multitude of devices for cleaning, polishing, finishing, inspecting, examining, or testing a fiber optic cable (including its bare ferrule surface and/or end connector). In one aspect, a universal connector/adaptor includes a universal outer portion and a detachable/interchangeable inner portion, where the universal outer portion and portions of the detachable/interchangeable inner portion can connect with any of the multitude of devices, and the detachable/interchangeable inner portion may hold a specific end connector, bare end surface, and/or fiber optic cable. In another aspect, a universal connector/adaptor kit may include a universal outer portion and a multitude of detachable/interchangeable inner portions, where each detachable/interchangeable inner portion is suited for a specific end connector, bare end surface, and/or fiber optic cable.

An optical fiber holder includes: a holder body including an accommodating portion, the accommodating portion being configured to accommodate a plurality of optical fibers in a state in which the plurality of optical fibers are arranged in parallel; and a first lid portion configured to be opened and closed relative to the holder body and cover at least a part of the accommodating portion. The accommodating portion includes a pitch conversion portion having a plurality of ridge portions arranged in parallel and a plurality of flat bottom portions between the plurality of ridge portions. The plurality of ridge portions have a uniform height of 0.1 mm or less from the bottom portions, and parallel intervals in between enlarge or lessen from one side toward the other side in a longitudinal direction.

A fusion splicing device according to an embodiment is a fusion splicing device of an optical fiber performing fusion-splicing by position-aligning the optical fiber that is a splicing target in a V-shaped groove. The fusion splicing device includes a microscope receiving light from a light source and passing through an optical fiber mounted on a V-shaped groove to obtain luminance information, a V-shaped groove driving unit moving the V-shaped groove, a storage unit storing a position of the V-shaped groove at which the microscope is focused, and an identification unit identifying the optical fiber. The position of the microscope is fixed. The V-shaped groove driving unit moves the V-shaped groove to a position stored in the storage unit. The identification unit identifies the optical fiber moved to the position.