Compact polarization splitter based on a silicon angled multimode interferometer structure

The difference between transverse electric (TE) and transverse magnetic (TM) mode-effective indices in a wave-guided angled multimode interferometer structure is found to produce practical polarization splitting (PS) in the silicon-on-insulator platform at 1550 nm. Simulations show that this PS offers competitive performance in low insertion loss (0.4 dB for TE and 0.8 dB for TM), high extinction ratio (ER) (27.6 dB for TE and 26.5 dB for TM), low cross talk (-27.3 dB for TE and -28.0 dB for TM), and a 53-nm bandwidth for ER>20 dB. The compact footprint (∼25 μm2), the identical single-mode input/output waveguides for integration without altering the cross section, and the simplicity in implementation are prominent advantages compared with prior art designs.