Fig. 2: Numerically designed metasurfaces for the generation of the LG10,200 mode.
From: Cascaded metasurfaces for high-purity vortex generation
a and b are the numerically calculated phase profiles for metasurface-1 and metasurface-2. c and d show the purity of vortex beam in Azimuthal index and radial index. e–h corresponds to the intensity profiles (top) and the phase distributions of modulated light at position P1-P4 marked in Fig. 1a. In our design, two metasurfaces are placed face-to-back, with an intermediate area containing 1.1 mm thick silica substrate and 0.2 mm air gap.
