Polymer-on-Silicon Microphotonic Bench

摘要

We report on a polymer-on-silicon optical bench platform that enables the hybrid integration of elemental passive and active optical functions. Planar polymer circuits are produced photolithographically on silicon wafers, and a variety of inorganic materials are integrated in them by chip-to-chip attach, insertion in slots, or flip-chip mounting. The polymer waveguides represent the state of the art in polymer photonics, and include properties such as ultra-low loss (0.1 dB/cm), large refractive index contrast (up to 30%), and large thermo-optic coefficient (-3 to -4x10~(-4)/℃). The organic circuits include interconnects, static routing elements such as couplers, splitters/combiners, and power taps, as well as thermo-optically dynamic elements such as tunable couplers, spatial switches, variable optical attenuators, and tunable notch filters, with the silicon acting as the heat sink. Arrayed waveguide gratings formed in silica and silicon oxynitride are used for multi/demultiplexing. Crystal-ion-sliced thin films of lithium niobate are inserted in the polymer circuit for polarization control or for electro-optic modulation. Films of yttrium iron garnet and neodymium iron boron magnets are inserted in order to magneto-optically achieve non-reciprocal operation for isolation and circulation. Ⅲ-Ⅴ semiconductor chips based on indium phosphide and gallium arsenide are integrated in order to achieve active functions including light generation, amplification, and detection, as well as wavelength conversion. The functions enabled by this multi-material platform span the range of the building blocks needed in optical circuits, while using the highest-performance material system for each function. We present photonic subsystems-on-a-chip based on this technology, including an intelligent optical crossconnect (iOXC), a fully reconfigurable optical add/drop multiplexer (R-OADM), and a tunable optical transmitter.