Ultrahigh extinction ratio of polarization beam splitter based on hybrid photonic crystal waveguide structures

• The hybrid waveguide structures of polarization beam splitter are all get by the optimization of the similar structure of graphene, they are combined with a high degree of compatibility without any additional compensation structure.
• The maximum extinction ratios of the TE and TM output ports are ultrahigh.
• The polarization beam splitter can have not only high transmission efficiency, but also ultrahigh extinction ratio.

A novel heterogeneous structure of two-dimensional photonic crystal polarization beam splitter is proposed, which is similar to the structure of graphene. Research and analysis in this paper are combined with the FDTD method. The results show that, the extinction ratio of the TE and TM output ports can reach over 95 dB and 60 dB respectively. The transmission efficiency for multiple normalized frequencies in the range from 0.3904 ωa/2πc to 0.4199 ωa/2πc are within −3 dB. When the normalized frequency is 0.4112 ωa/2πc, the transmission efficiency is −0.13 dB and the extinction ratio is 31.76 dB at the TM output port, the transmission efficiency is −0.04 dB and the extinction ratio is 80.54 dB at the TE output port. This polarization beam splitter has not only high transmission efficiency, but also ultrahigh extinction ratio. These features have important application prospects in integrated optical circuit, optical communication and other fields.