Novel Polarization Rotators for Silicon Photonic Integrated Circuits

Abstract

We present a novel mode-interference based polarization rotator with a dual-waveguide structure based on the standard silicon-on-insulator substrate. The polarization rotator section consists of two non-identical nanowire waveguides arranged 45° offset with regard to the other. Two identical dual-taper sections are introduced in-between this polarization rotator and the standard silicon input/output waveguides to realize equal modal excitation amplitudes of two hybrid modes in the polarization rotator section. Simulation results show that this device with the total length of 25.3 μm has the insertion loss of −0.51 dB and the extinction ratio of 32.27 dB for TM → TE mode conversion at the wavelength of 1550 nm and the extinction ratio of over 20 dB at thewavelength ranging from 1536 nm to 1568 nm.