Design of polarization beam splitter in two-dimensional triangular photonic crystals

A design of a polarization beam splitter (PBS) in two-dimensional triangular photonic crystals is proposed and numerically demonstrated, for the first time to our knowledge. The principle of the model is based on the polarization dependence of the photonic band gaps in photonic crystals; the polarization extinction ratios for transverse-magnetic and transverse-electric modes are 11.5 dB and 46.7 dB at the centre of its operating frequency range, respectively. When the central wavelength is tuned at 1550 nm, the possible operation wavelength range of this structure can be as large as 28.5 nm, which almost covers the whole C band in modern optical communication systems. Furthermore, due to its small size and only one kind of material being involved, the PBS structure may have practical applications in the integrated optics field.