Lingxuan Zhang’s research team numerically investigate the polarization beam splitter (PBS) based on the directional coupler to operate transverse-electric (TE) and transverse-magnetic (TM) modes including high-order modes. Based on the phase-matching condition, all TM-polarization modes are switched from the bus waveguide to the adjacent waveguide without changing the spatial profile of the electric field and mode order while all TE-polarization modes go along the bus waveguide without significant coupling. The results show a low cross talk characteristic (>20 dB at 1.55 mu m) and big fabrication tolerance (delta w = +/- 20 nm). It becomes an essential supplement for polarization splitting with multimode operation in photonics integrated circuits.

（Original research article "Japanese Journal of Applied Physics Vol. 58, Issue 1, 010905 (2019) https://iopscience.iop.org/article/10.7567/1347-4065/aaef92"）