Experiments and Simulations of Infrared Transmission by Transverse Magnetic Mode through Au Gratings on Silicon with Various Air-slot Widths over the Period

Au gratings with various air-slot widths were fabricated by electron beam lithography system (e-beam) and their infrared (2.5~25μm) transmission of the transverse magnetic mode (TM mode) were investigated by the Fourier Transform Infrared Spectroscopy (FTIR). Simulations were used theoretically by the Maxwell equations and the surface impedance boundary condition (SIBC) method. Simulation results explain the relationship between surface plasma and transmission dips.