High extinction ratio silicon polarization beam splitter with tolerance to waveguide width and coupling length variations.
We demonstrate a compact silicon polarization beam splitter (PBS) based on grating assisted contradirectional couplers (GACCs) Over 30 dB extinction ratios and less than 1 dB insertion losses are achieved for both polarizations. The proposed PBS exhibits tolerance in width variation, and the polarization extinction ratios remain higher than 20 dB for both polarizations when the width variation is adjusted from 10 to 10 nm. Benefiting from the enhanced coupling by the GACCs, the polarization extinction ratio can be kept higher than 15 dB and the insertion loss is lower than 2 dB for both polarizations when the coupling length varies from 30.96 to 13.76 mm.
Optics express