Terahertz metasurface for flexible band-pass filter

We present a coupled mode theory (CMT) to design terahertz flexible band-pass filter. Based on this theory, we designed three band-pass filters with passband 0.74-0.89, 0.72-0.91 and 0.72-0.95THz. The transmission in the passband is all above 80%. This method can be easily extended to other frequency regime.