Figure 1: Schematic of basic unit cell in the simulation and interference pattern.
From: Generation and detection of orbital angular momentum via metasurface
(a)The unit cell of the elliptical nanohole milled in a thin gold film. The elliptical nanohole can be rotated in the x-y plane with an orientation angle θ to create a different phase delay. (b)The phase shifts and transmission of the cross-polarized light as the function of the orientation angle θ with a RCP incidence at wavelength of 632.8 nm. The long axis and short axis length of the nanohole in the simulation are a = 180 nm, b = 90 nm, respectively. (c) The sketch of the interference pattern. The regions I and II are used to generated vortex beam with OAM and spherical beam, respectively. The green pattern and red pattern behind the sample represent spherical beam and vortex light, respectively. The insert images are the interference intensity distribution. The polarization state of the incident light and transmitted light is presented by the space-variant arrows.
