Novel Wide-Bandwidth Polarization Filter Based on H-Shaped Micro-Structured Optical Fiber with Gold Nano-strip

This work describes the design and analysis of a polarization filter by excitation of surface plasmon polaritons (SPPs) in an H-shaped microstructured optical fiber with gold nano-strip. Numerical results based on the vector finite element method show that the excitation of the SPPs is different in two polarized directions, covering the S and C optical communications bands. We found that by varying the geometrical parameters of both the fiber and the gold nano-strip, it is possible to modify the crosstalk of device and, consequently, tuning the central wavelength and the bandwidth of the polarization filter. The strength of the SPP excitation that we obtain can reach values of ~3200 dB/cm and ~1600 dB/cm at around 1310 nm and 1550 nm, with bandwidths of ~120 nm and ~180 nm, respectively.