Optical transmitter including splitting elements, external modulators, and wavelength multiplexers, and optical transceiver including polarization separation elements, wavelength demultiplexers, polarization rotation elements, and photodetectors

Abstract

An optical transmitter splits each of pieces of continuous wave light with N different wavelengths into M, and includes: a plurality of splitting elements to each split input light into two, N of the plurality of splitting elements to which the pieces of continuous wave light with N different wavelength are input being included in each of splitting blocks arranged at j=logM stages; N×M external modulators to modulate respective pieces of the continuous wave light obtained by splitting at splitting elements at a j-th stage; and M wavelength multiplexers to multiplex every N different wavelengths of light after being modulated output from the external modulators, and the plurality of splitting elements are connected in such a manner that arranging order of N wavelengths that are input to an upstream splitting block and arranging order of N wavelengths that are input to each of downstream splitting blocks are identical.