Design of a fiber polarizer based on an asymmetric dual-core photonic crystal fiber

We propose a novel optical polarizer based on an asymmetric dual-core photonic crystal fiber (PCF) with triangular lattice air-holes. The fiber is designed as that the effective indices of modes in the two cores are matched at one polarized state but mismatched at another polarized state. As a result, one of the polarization states is coupled to the other core and transferred into a high-order mode. The transmission properties of the polarizer are investigated by the semi-vectorial beam propagation method (SV-BPM). Numerical results demonstrate that a device length of 11.3 mm shows extinction ratio as low as -20 dB with bandwidth as great as 80 nm ranging from 1.51 m to 1.59 m. © 2011 Tianjin University of Technology and Springer-Verlag Berlin Heidelberg.