Polarization properties of an acousto-optic photonic crystal fiber filter

We investigate the polarization dependent characteristic of an acousto-optic filter in an endlessly-single-mode photonic crystal fiber and find that polarization dependence is high. The maximum wavelength shift due to polarization is ∼ 2.25 nm and the polarization dependent loss is ∼4.00 dB. The wavelength shift direction is different for different resonant dips in the acousto-optic filter when a polarized broadband light source is used as the input source, which is different largely compared with an acousto-optic filter based on a conventional single-mode fiber.