Optical element, mold for the optical element, method for manufacturing the optical element and bidirectional optical communication module

摘要

An optical element used in a bidirectional optical communication module used for bidirectional optical fiber communication by a wavelength multiplex system, comprising a diffraction grating of binary structure prepared by molding, wherein a taper is formed at a portion of the diffraction grating where light entering the diffraction grating is intercepted by a convex part of the binary structure of the diffraction grating.