Photonic Integrated Circuits

Abstract

Photonic integrated circuits based on a silicon-on-insulator platform attract much attention due to their high density integration and compatibility with the complementary metal–oxide–semiconductor (CMOS) fabrication process. This chapter presents two examples of integrated circuits with a focus on passive silicon photonic devices: one is related to high speed receiver and the other is on switching. We first illustrate the schematic and testing of an integrated coherent optical receiver. Edge couplers, polarization splitter-rotators, waveguide crossings, 90° hybrids, and germanium photodetectors are included in the integrated coherent receiver chip. Coherent detection of a 224-Gb/s polarization-division-multiplexed 16-ary quadrature amplitude modulation signals is demonstrated using the receiver chip. We then discuss a mode-polarization-wavelength selective switch by leveraging three physical dimensions consisting of mode (de)multiplexers, polarization beam splitters, multimode interferometer, waveguide crossings, and tunable micro-ring resonators. The building blocks and the switching chip are experimentally demonstrated.