Figure 3.

Comparison of optical properties of three different structures in TE mode: (a) plasmonic dimer lines of gold NPs with 520 nm periodicity supported by photoresist gratings on a glass substrate. Both experiment and simulation studies show a broad particle resonance around 1000 nm for excitation with TE polarization along the chain directions. Variation of the incidence angle experimentally exhibits a constant broad dip which is also supported by simulations. (b) Dielectric GMR structure with a photoresist grating (of periodicity 520 nm and thickness 150 nm) on a TiO₂ waveguide (of 200 nm thickness) and a glass substrate. Experimental as well as simulation studies observe transmission dip at 921 nm for normal incidence, whereas splitting of modes occurs on varying the AOI. (c) Hybrid plasmonic–dielectric resonant structure with gold NP dimer lines filled within the grating lines of a dielectric GMR. At normal incidence, two hybrid modes are excited at different wavelengths. Scanning of the incidence angle reveals the interaction of the broad plasmonic mode with the photonic GMR mode at higher angles, as observed from both experimental and simulation data.