Eight-Channel WDM Intraboard Optical Interconnect Device by Integration of Add/Drop Multiplexers in Thin-Film Waveguide

A wavelength-division-multiplexing (WDM) optical interconnect device has been proposed and investigated in order to realize broadband signal transmission in intraboard chip-to-chip interconnection. Focusing grating couplers (FGCs) and distributed Bragg reflectors were integrated in a thin-film waveguide to form free-space-wave add/drop multi-/demultiplexers for the WDM optical interconnections. This time, FGC coupling efficiency was improved by careful fabrication with multistep deposition and measurements of reflection spectra. An eight-channel WDM interconnect device was fabricated and characterized in the wavelength dependence.