Liquid crystal photonic bandgap fiber: different bandgap transmissions at different temperature ranges

The temperature tuning properties of a liquid crystal (LC) photonic bandgap fiber's bandgap transmission was investigated in this study. Because of the special temperature responses of the LC's indices and its phase transition property, the bandgap transmission was found to have different temperature responses at different temperature ranges below the LC's clearing point temperature. At temperatures lower or higher than the LC's clearing point, the bandgap transmissions are quite different, which permits switching with an extinction ratio as large as 45 dB. At temperatures around the LC's clearing point, the bandgap transmission was depressed.