Tunable thermo-optic switch based on fluid-filled photo- nic crystal fibers

A tunable thermo-optic intensity-modulated switch is investigated theoretically and numerically. It is based on the infiltration of temperature-sensitive mixture liquids into index-guiding photonic crystal fibers （PCFs）. The switching function attributes to the thermo-optic effect of the effective refractive index of the cladding. The simulation illustrates that the switch presents a tunable transition point according to the concentration of the mixture liquids, and the on-off switching functionality can be realized within a narrow temperature range of 2 ℃. The switches have wide application for innovative all-in-fiber optical communication and logic devices.