Optical attenuator

摘要

An optical attenuator includes a holding sleeve, a pair of ferrules inserted into and fixed to the holding sleeve such that the ferrules oppose each other at base ends thereof at a predetermined distance between each base end, and an attenuating fiber inserted into and fixed to the pair of ferrules such that ends of the attenuating fiber are exposed. The optical attenuator is also provided with an opening in the holding sleeve so as to communicate with the outside. A filler is supplied into the sleeve through the opening.