Terahertz wave filter based on photonic crystal

In the past decade, spectroscopy and imaging in the terahertz region (0.1-10 THz) of the electromagnetic spectrum has been applied in both basic research and potential industrial applications, such as medical diagnosis, security screening, radio astronomy, atmospheric studies, short-range indoor communication, chemical, biological sensing, medical and biological imaging, and detection of explosives. In this paper, we design a narrow bandpass terahertz wave filter using three kinds of two-dimensional photonic crystals. By using finite-difference time-domain (FDTD) method, we examined the transmittance spectra for the proposed terahertz wave filter. The simulated results show that the proposed filter exhibit excellent transmission performance such as high transmission at the central frequency, adjustable bandpass, and good rejection of the sideband frequencies.