Fig. 2.

Spectral transmission of Ag based nanocavities with and without the metasurface. a Cross-sectional schematic of the metasurface-based nanocavity. P and W are the perodicity and linewidth of Ag grating, respectively. T_p is the thickness of polymer layer. The thickness of both top and bottom Ag mirror is 15 nm and the thickness of grating is 22 nm. b 30° tilted view and Top view of FE SEM (Field Emission Scanning Electron Microscopy) image of fabricated nanocavity. Experiment (c, e) and simulation (d, f) of transmission spectra of nanocavity with 60 nm thick polymer spacer (inset in c: the schematic of polarization direction, θ is the angle of polarization of incident wave): c, d θ = 0° and e, f θ = 90°