Figure 2. Simulated optical modes.

(a–c) Computed 2D spatial profiles of the electric field modulus for the higher Q optical modes of Fig. 1c: (a) P, (b) L, and (c) H. (d–f) Fourier transform of the optical mode spatial profiles (upper left) in the reciprocal space for (d) P, (e) L, and (f) H (upper left half), plotted together with the form factor of the designed quasi crystal (bottom-right half). f(k) peaks at values k_p identified by heavy dots. To identify the Bragg peaks responsible for the feedback, one can overlap the circles of radius nk_p, for each n corresponding to values that satisfy the Bragg equation; the circumference with n=(1+√5)/2 is shown in blue in (d) and perfectly intersects strong resonances of indicating a five-wave diffraction as the origin of the feedback for the related optical mode P. The circle of radius k_p is also plotted in pink to show Bragg peaks of S(k) responsible for vertical extraction.