In-fiber polarizer based on a long-period fiber grating written on photonic crystal fiber

Abstract

A novel in-fiber polarizer based on a long-period fiber grating (LPFG) is written by using a focused CO₂ laser beam to notch a photonic crystal fiber periodically. Such a polarizer exhibits a high polarization extinction ratio of more than 20 dB over a wide wavelength range of ∼11 nm near 1550 nm and a very low temperature sensitivity of 3.9 pm/°C, which overcomes the disadvantages of the temperature sensitivity of other in-fiber polarizers created on conventional single-mode fiber.