Ultrabroad Bandwidth Polarization Filter Based on D-shaped Photonic Crystal Fibers with Gold Film.

An ultrabroad bandwidth polarization filter based on D-shaped photonic crystal fibers with gold film is proposed. The design of gold film deposited on the polished plane of the D-shaped photonic crystal fibers is benefit to generate multiple resonances between surface plasmon polaritons and photons. In our designed polarization filter, the resonant intensity in y-polarization direction is much stronger than in x-polarization direction. An ultrabroad bandwidth of exceeding 1 μm with extinction ratio better than -20 dB is obtained. The performance characteristics of the filter can be improved further by optimizing the structure parameters of the D-shaped photonic crystal fibers. [ABSTRACT FROM AUTHOR]