FIBER EQUIPPED WITH LENS

摘要

A fiber equipped with a lens, which can be connected with an optical semiconductor device at improved coupling efficiency. This fiber (10) has a structure in which a coreless fiber (12) having an isotropic refractive index and having a convex end is connected at the other end to one end of a single-mode fiber (11) having a core (11a) and a clad (11b) through a fiber (13) having a square refractive index distribution.