MULTIPLE-WAVELENGTH OPTICAL MODULATION CIRCUIT AND WAVELENGTH-MULTIPLEXING OPTICAL SIGNAL TRANSMISSION APPARATUS

摘要

PROBLEM TO BE SOLVED: To demultiplex multiple wavelength light having bandwidths more than the free spectral range (FSR) of an arrayed-waveguide grating (AWG) into individual wavelength channels, and suppress power level deviation between each wavelength channels. SOLUTION: A demultiplexer is constituted of a group demultiplexer 31 which demultiplexes the multiple wavelength light into wavelength groups each having a plurality of wavelength channels, and a plurality of channel demultiplexers 32-1 through 32-m which demultiplex each wavelength group into light containing a plurality of wavelength channels. A multiplexer is constituted of a plurality of channel multiplexers 34-1 through 34-m which multiplex modulation signal light of each wavelength channel on a wavelength group-by-group basis, and a group multiplexer 35 which multiplexes the wavelength-multiplexed signal light in each wavelength group output from each channel multiplexer. The FSR of the group multiplexer/demultiplexer is set more than the bandwidth of the multiple wavelength light. As a channel multiplexer/ demultiplexer, there is employed an AWG of which FSR is approximately full width at half maximum (FWHM) of transmission characteristic of each port in the group multiplexer/demultiplexer.