Terahertz switch and polarization controller based on photonic crystal fiber

Theoretical studies on liquid crystal filled photonic crystal fiber （LC-PCF） are presented. The effects of electric birefringence of liquid crystal （LC） in the LC-PCF and the transmitting properties of photonic crystal fiber （PCF） are investigated by using the full vector plane wave expansion and beam propagation method. The simulation results show that the electrically controlled LC-PCF can act as not only a terahertz （THz） switch with about 0.55 THz bandwidth, but also a tunable polarization controller for changing the polarization state of the fundamental mode.