Polarization-diversity silicon photonic Mach-Zehnder delay interferometer for optical signal processing integrated with a phase-controllable polarization beam splitter

Abstract

This study investigates a polarization-diversity Mach-Zehnder delay interferometer (MZDI) for optical signal processing integrated with a polarization beam splitter (PBS) using silicon photonics technology. The PBS consists of two-stage MZDIs. By using the birefringence of the silicon waveguide and controlling the phase with thermal heaters on MZDIs, the polarization extinction ratio (PER) of the PBS was improved. MZDIs with a free spectral range (FSR) of 40 GHz in both TE and TM modes were designed using the group index for both polarization modes. The PER of 40-GHz-FSR MZDIs for TE and TM modes of 15 and 10 dB, respectively, within the C-band were observed.