Characterization of Optical Redistribution Loss Developed for Co-Packaged Optics

We previously proposed a new package substrate called active optical package (AOP) substrate to realize co-packaged optics. An optical redistribution technology on silicon photonics dies was developed to fabricate the AOP substrate. It is composed of a polymer waveguide, with a mirror-based optical coupling between the polymer and silicon waveguides. The fabricated optical redistribution loss was characterized in this study. An average loss of approximately 4 dB and wavelength dependent loss of ±1 dB were observed for the wavelength range of 1460–1600 nm. It was shown that the low wavelength-dependent optical redistribution was available owing to the broadband characteristics of mirror-based optical coupling and polymer waveguide.