Moiré fringes characterization of surface plasmon transmission and filtering in multi metal-dielectric films

Abstract

We use moiré fringes to experimentally characterize the transmission and filtering effect of surface plasmons (SPs) in the alternatively stacked metal-dielectric layers (ASMDLs). Two gratings with unequal periods are introduced at the two sides of films structure to excite SPs and generate moiré fringes observable in the far-field. The observed moiré fringes with specific period agree well with simulations and clearly demonstrate SP with corresponding wave vector transmission and filtering in ASMDLs. By applying variant incidence angle, the fringes contrast fluctuation further illustrate the transmission of SP in a specific wide wave vector band and with an uneven amplitude transmission profile.