Surface-plasmon-polariton (SPP) wave excitation in a composite structure obtained by depositing a columnar thin film (CTF) on a metal (silver) substrate decorated periodically by an array of rectangular grooves was analyzed using the rigorous coupled-wave approach. The SPP wave is excited as a Floquet harmonic of different orders by light incident from different directions, the incidence plane being the same as the grating plane. But, in some instances, the SPP wave appears to be excited as a doublet, i.e., a Floquet harmonic of the same order at two closely spaced angles of incidence, the excitation being less efficient for one angle of incidence than for the other. The characteristics of the SPP wave are affected by the vapor incidence angle chosen to deposit the CTF.
All Science Journal Classification (ASJC) codes
- Atomic and Molecular Physics, and Optics