Optical wavelength division multiplexer

Abstract

In an optical wavelength division multiplexer, flattening of band characteristic can be realized while reducing excessive loss due to the flattening of band characteristic in an arrayed waveguide grating. Further, the flat band of the band characteristic can be made broader. The optical wavelength division multiplexer according to the invention includes: a first coupler optical waveguide 104 and a second coupler optical waveguide 106; one or more input side connecting part waveguide(s) 103 with one end connected to an input optical waveguide 101 and the other end connected to an optical input end face of the first coupler optical waveguide 104; one or more output side connecting part waveguide(s) 103′ with one end connected to an output optical waveguide 107 and the other end connected to an optical output end face of the second coupler optical waveguide 106; and an arrayed optical waveguide 105 connected between the first coupler optical waveguide 104 and the second coupler optical waveguide 106 and having plural channel waveguides with different lengths from one another, and further includes an optical interferometer connected to at least two optical waveguides between the input side connecting part waveguide 103 and the input optical waveguide 101. The optical interferometer includes a ring structure 202 that feeds back an input light, and is provided so that an interference period of the optical interferometer may become equal to a difference between frequencies of light output from adjacent optical waveguides of the output side connecting part waveguide 107.

Dependencies are inferred from the claim text.