Wavelength Switchable Terahertz Filter Based on Photonic Crystal with Liquid-Crystal Defect Layer

Electrically controlled wavelength switchable terahertz band pass filter based on photonic crystal structures with LC defect layer is proposed and discussed. The wavelength switching can be realized by reorienting liquid crystal molecules through adjusting the applied electric field. Numerical analyses results have shown that the proposed structure has the potential to realize electrically controlled terahertz filter with a high narrow transmission band and very sharp edges. What s more, the device can also function as a terahertz switch, and the theoretical extinction ratio of the device can reach more than 50dB.