200 nm K p k$_{x}$ p 8 -8 FIG. 8. Intensity | h$_{x}$ | 2 in the transverse xy plane for a nondiffracting beam of β = 10 . 16 µ m − 1 and γ = 16 . 55 µ m − $^{1}$. Excitation of Bloch modes with | k$_{x}$ | < 5 . 15 µ m − 1 leads to nonevanescent wavelets in the dielectric slabs, so that the resulting hybrid wavefield from Eq. (5) combines Bloch constituents of different nature. 30