Integration of optical devices based on Si, Ge and SiOx

Monolithic integration of various kinds of optical components on a silicon wafer is the key to making silicon photonics practical technology. Applying silicon (Si) photonics to telecommunications further requires low insertion loss and polarization independence. We demonstrate monolithic integration of Si variable optical attenuators, germanium photodiodes, a SiOx-based arrayed waveguide grating filter, and a spot size converter that connects each component with low loss. Moreover, We also show a method for achieving low polarization dependent loss in a Si-VOA. Our results indicate the great potential of silicon photonics technology for optical devices in telecommunications.