Figure 4
From: A compact diffractive sorter for high-resolution demultiplexing of orbital angular momentum beams
SEM inspection of the 3-copy sorter fabricated with electron-beam lithography and designed for λ = 632.8 nm. Number of phase levels: 256. Maximal thickness step: 1289.0 nm. (a) Zone of transition from the inner (double phase-corrector) to the outer (fan-out unwrapper) region marked by a green line in Fig. 3(a). (b–e) Details. (f) Region marked by an orange line in Fig. 3(a). (g) Exposure of a limited part (40 × 40 μm2) of the region in figure (f) in order to highlight the edge profile.
