Patent ID: 6760510
Filing Date: 2004-07-06
Classification: G02B

Abstract:
A wavelength multiplex optical communication module comprising:a light emitting device disposed on an optical waveguide substrate; a first optical waveguide for guiding signal light with a first wavelength output from said light emitting device; a second optical waveguide that has a path connecting one end face of the optical waveguide substrate to the other end face of the optical waveguide substrate and has a portion of the waveguide, between both ends of the path, which is disposed closely to the first optical waveguide to constitute a directional coupler for transferring the power of the signal light with a first wavelength at a predetermined ratio to the second optical waveguide; a wavelength filter disposed at said other end face of the optical waveguide substrate, for reflecting the signal light with a first wavelength and, in addition, permitting signal light with a second wavelength different from the first wavelength to be transmitted therethrough; a third optical waveguide that has a path connecting one end face of the optical waveguide substrate to the other end face of the optical waveguide substrate and is disposed in such a manner that the end of the third optical waveguide and the end of the second optical waveguide face the wavelength filter on said other end face side of the optical waveguide substrate so that, according to reflecting characteristics of the wavelength filter with respect to a predetermined wavelength, a reflected light, which has been guided through the second optical waveguide and reflected from the wavelength filter, is coupled to the third optical waveguide while a reflected light, which has been guided through the third optical waveguide and reflected from the wavelength filter, is coupled to the second optical waveguide; and an out-of-substrate photodetector that is provided outside the optical waveguide substrate so as to face said other end face of the optical waveguide substrate through the wavelength filter and receives the signal light with a second wavelength which has passed through the wavelength filter.