Tunable and rotatable polarization controller using photonic crystal fiber filled with liquid crystal

We design and fabricate a compact tunable and rotatable polarization controller using liquid crystal photonic band gap fibers. The electrically and thermally induced phase shift in the Poincaré sphere and corresponding birefringence change are measured. The direction of the electric field is managed by connecting four electrodes in different electrode configurations, and the thermal tunability is controlled by on-chip heaters.

According to the results, a quarter-wave plate and a half-wave plate working in the wavelength range of 1520–1600 nm are experimentally demonstrated.