Wide-passband, temperature-insensitive, and compact pi-phase-shifted long-period gratings in endlessly single-mode photonic crystal fiber

Polarization-dependent coupling in gold-filled dual-core photonic crystal fibers

We numerically investigate the polarization-dependent coupling in dual-core photonic crystal fibers (PCFs) selectively filled with gold wires in air holes. It is shown that the even and odd supermodes exhibit significantly different dispersion and loss when one gold wire is filled in between two cores. The enhanced birefringence and polarization-dependent attenuation of the supermodes support the separation of two orthogonally polarized components as well as polarization-dependent transmissions with a high degree of polarization in gold-filled dual core PCFs. Our study suggests that a gold-filled PCF coupler is a new possibility for applications on polarization beam splitters and polarizers.

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

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/ degrees C, which overcomes the disadvantages of the temperature sensitivity of other in-fiber polarizers created on conventional single-mode fiber.