Wideband reflector and bandpass filter by using a Ge subwavelength periodic membrane

Abstract

Wideband reflector and bandpass filter are obtained by using a Ge subwavelength periodic membrane with the thickness kept constant at 3.20 μm. The strong refractive-index modulation of the Ge subwavelength periodic membrane yields increased bandwidth of the leaky mode resonances, thus the excitation of the leaky mode resonances TE1,1, TE2,1, and TE3,0 may interact to form a broad reflection band or a transmission passband near λ=10.60 μm.