Fig. 6: Optimization results for polarization-multiplexed metalenses.

a Schematic of a cross section of the proposed device where incident light is focused to two different focal spots controlled by the linear polarization state of the input. The black arrows indicate the direction of light propagation, the orange dotted line designates the focal plane, and the green arrows represent the orientation of the distinct horizontal and vertical polarization states of the foci. The product of the electric field magnitudes at the two different focal spots is optimized (b) and the resultant intensity at the focal plane for vertical (c) and horizontal (d) polarizations exhibit distinct focal spots. Focusing in the y–z plane for each polarization state for the optimized design is shown in (e), with near-field data computed using finite-difference time-domain simulation. TE and TM in (b) stand for the transverse electric and transverse magnetic polarization states, whereas \(E^{f_1}\) and \(E^{f_2}\) denote the electric fields at the two optimized focal spot positions.