Fig. 2. Boundary phase shift and impact on resonant mode in a single groove.

a Analytically calculated phase shift of an Ag-MgF₂-Ag cavity with respect to groove width in the visible range. b Analytically calculated resonant groove length of the same cavity in relation to the groove width and length with (solid lines) and without (dotted lines) the inclusion of the phase shift φ at the boundary. Numerical simulation data (circular markers) are shown for select geometries. The presented data is for the first resonant mode m=1