Compact polarization splitter based on plasmonic micro-structured fiber

Micro-structured fiber (MF) devices such as polarization rotators, polarization filters, and polarization splitters have been widely used in optical communication systems. The concept of multifunctional photonic device becomes a new trend in optical systems. Therefore, it is essential to propose a new and compact multifunctional MF widely known as photonic crystal fiber (PCF) devices. In this paper, a compact polarization splitter that operates at two telecommunication wavelengths (1.31 μm or 1.55 μm) is designed. The proposed splitter is based on plasmonic tellurite dual core PCF in order to split the x and y polarization modes at wavelengths of 1.31 μm or 1.55 μm at the same device length. The nematic liquid crystal is selectively infiltrated in the cladding air holes to increase the birefringence in the introduced design. Further, the central hole is filled by a gold nanowire. The simulation results are obtained by using full vectorial finite element method with perfect matched layer boundary conditions. The numerical results reveal that the suggested splitter can split the x and y polarized modes at λ=1.31 and 1.55 μm at a short device length of 131.0 μm. The obtained crosstalk is -38 dB and -48 dB with bandwidths of 58 nm and 48 nm at λ= 1.31 μm for x and y polarized modes, respectively. In addition, crosstalk of -56 dB and -47 dB are achieved with bandwidths of 124 nm and 88 nm at λ= 1.55 μm for x and y polarized modes, respectively.