Figure 5.

A) Reflection spectra (zero-order diffraction efficiency) of the designed filters. The parameters chosen are: Λ = 2.2, 2.3, 2.4 and 2.5 μm, f = 0.5, d^gr = d^wg = 0.3 μm, n^Si₃^N₄ = 2.0, n^S = 1.48, n^c=1.0. B) E-field distribution in the vicinity of structure with Λ = 2.5 μm at a resonant wavenumber, ν̄= 2659 cm⁻¹ (top) and off-resonance wavenumber, ν̄ = 3400 cm⁻¹. The surface relief of the film to be fabricated is depicted using white lines.