Extraordinary Optical Transmission Exhibited by Surface Plasmon Polaritons in a Double-Layer Wire Grid Polarizer
We fabricate a double-layer wire grid polarizer (WGP) and perform optical characterization to clarify the relationship between the structural and polarization characteristics. For normal incidence, the fabricated double-layer WGP exhibits an extinction ratio of 30.4 dB for a period of 400 nm. The transverse magnetic transmittance peak angle is found to vary with the period of the WGP. The peak shift can be explained on the basis of the extraordinary optical transmittance phenomena exhibited by the surface plasmon polaritons (SPPs) of metal slit structures according to the dispersion curve of the SPP. From the simulation of rigorous coupled-wave analysis, it is considered that the incident light passes through the resist layer, followed by the excitation of SPPs at the interface between the resist and Au. Subsequently, the SPPs combine with the transmitted light in the glass substrate, leading to strong transmitted light with transverse magnetic polarization. Therefore, we demonstrate the extraordinary optical transmittance phenomena exhibited by the SPPs by both experiment and simulation.
KeywordsWire grid polarizer Polarization property Surface plasmon polariton Extraordinary optical transmittance phenomena