Polarization splitter using asymmetric sidewall long-period waveguide gratings in a two-mode silicon waveguide

We demonstrate a silicon polarization splitter, which uses sidewall long-period waveguide gratings for coupling between the two core modes. The TM- and TE-like modes are divided in an asymmetric Y-branch. The measured maximum cross-talks of the TM-and TE-like modes are 15.8 and 15.1 dB, respectively. The extinction ratios of port I and II are 18.3 and 12.6 dB, respectively.