Fig. 1.
The geometry and coupled resonances of a NW GSL. a Structure and illumination geometry of a Si NW GSL. b Schematic illustration of a leaky Mie resonance with a broad spectral envelope (left) and a continuum of BGS states (right), in which a specific BGS state, ωg, is selected by the choice of pitch p. c Numerically calculated spectra of Qsca (solid lines) and analytical fit by TCMT (dotted lines) for an infinite NW with uniform d (δ = 0) of 140 nm (gray) and for NW GSLs with d = 140 nm, e = 135 nm, and varying p of 360 nm (orange), 420 nm (red), and 500 nm (brown). The pitch, p, in nanometers is denoted for each spectrum, where p = ∞ corresponds to an infinite NW of uniform diameter d. All spectra are successively offset vertically by 10. d–f Schematic and calculated magnetic field profiles for a GSL with p = 420 nm at frequencies of ω+ (d), ω− (e), and ωg (f), corresponding to the red spectrum and labels in c at wavelengths of 692, 713, and 703 nm, respectively