Integrated-Optic Free-Space-Wave Coupler for Package-Level On-Board Optical Interconnects

A cavity-resonator integrated grating input/output coupler (CRIGIC) gives high-efficiency vertical coupling with small aperture suitable for high-density intraboard optical interconnection. Design and preliminary experimental results of simple CRIGIC on a Si substrate were described. Integration of CRIGIC and a different-guided-mode-coupling distributed Bragg reflector was proposed and discussed to provide free-space-wave optical add/drop multiplexing (FOADM) function for an application to a future high-performance signal-processing system in package using wavelength division multiplexing optical interconnection. A scheme of eight-wavelength multiplexing system within 20-nm wavelength range was investigated. FOADM devices were designed and their performances were simulated theoretically.