Broadband Thermo-Optic Switching Effect Based on Liquid Crystal Infiltrated Photonic Crystal Fibers

We demonstrate a liquid-crystal-filled photonic crystal fiber (PCF) and investigate its temperature response with a unique liquid crystal (LC) clearing point of 58 °C. Opposite temperature responses are observed at the temperature that is lower and higher than the LC's clearing point, respectively. Such a LC-filled PCF could be used to develop a promising optical switch with a broadband operation range of 102.5 nm via a small temperature change of less than 1.5 °C. Moreover, the LC-filled PCF exhibited an ultrahigh temperature sensitivity of 105 nm/°C and could find potential applications in the field of temperature sensors.