Fig. 2
From: Phyllotaxis-inspired nanosieves with multiplexed orbital angular momentum
Simulation and experimental results of the free-space phyllotaxis-inspired vortex nanosieve. a, b Simulated intensity (a) and phase (b) profiles of the free-space phyllotaxis-inspired vortex nanosieve. c A top-view scanning electron microscope (SEM) image of the sample. d The measured free-space Fresnel diffraction intensity profiles upon 633Â nm, 532Â nm, and 445Â nm illumination, respectively