Fig. 2: Design principle and optical simulation of the chiral metasurface and VCDG for CP and LP detection.
From: Chip-integrated metasurface full-Stokes polarimetric imaging sensor
a–h Design of the chiral metasurface and VCDG for CP and LP detection (a) 3D schematic and 2D cross-section of VCDG. The thickness(tAl) of Aluminum (Al), width(wAl), period(p1), and the vertical gap (g) of VCDG are optimized to be tAl = 80 nm, p1 = 190 nm, wAl = 95 nm and g = 30 nm, respectively. b Cross-sectional view of VCDG near field distribution with input light (650 nm) polarized along x axis. c Transmission spectra and LPER of VCDG with input light polarized along x and y axis respectively. d 3D schematic and 2D cross-sectional view of the top layer Si nanograting and bottom layer VCDG, respectively. The thickness (tsi), period (pSi), width (wSi), and tilted angle (θSi) of Si nanograting are tsi = 130 nm, pSi = 297 nm, wSi = 100 nm and θSi = 6° respectively. The thickness (tAl) of Aluminum (Al), period (p2), and vertical gap (g) of bottom layer VCDG are optimized tAl = 80 nm, p2 = 210 nm, and g = 30 nm, respectively. The thickness of the SiOx spacer layer is t = 400 nm. e Near field distribution of the Si grating when incident polarization is along the width of the Si nanogratings (U axis) and length of the Si nanogratings (V axis) at 629 nm. f Simulated transmission spectra(left) and CPER (right) of dielectric-metal hybrid chiral metasurface at 550 nm-750 nm. The red shadow region indicates the wavelength range for CPER over 10. g Near field distribution of the Si grating when incident polarization is along the U and V axes at 500 nm. h Simulated transmission spectra(left) and CPER (right) of dielectric-metal hybrid chiral metasurface at 400 nm-550 nm. The blue shadow region indicates the wavelength range for CPER over 10
