Fig. 7: Variations of the Goos–Hänchen lateral shift.
From: Correcting the formalism governing Bloch Surface Waves excited by 3D Gaussian beams
a, in the case of N = 7 as a function of the beam-waist for three different values of the imaginary part of the refractive index of the media (all the layers except the glass substrate and air obviously). The blue curve corresponds to the loss-less case while the red and green ones correspond to n″ = 10−4 and n″ = 10−3 respectively. The yellow, ocher and purple vertical thick lines correspond to three different values of the beam-waist W0. All the three curves in a correspond to values calculated within the Transfer Matrix Method (TMM) combined to the Plane Wave Expansion (PWE) algorithm while the circles are obtained from Eq. (5). b, Comparison between TMM/PWE results (solid line) and values calculated from Eq. (5) (green circles) of the LGH as a function of n″ in the case of a fixed value of the beam-waist (W0 = 300 μm).
