LAUSR

Abstract In this paper, we propose a method to construct geometric-phase-based spin Hall metalens, which consists of identical metal nanoholes with spatially variant orientations. It is demonstrated that the metalens can realize simultaneous focusing for different spin states in the broad spectral range of 550–900 nm due to the extremely similar hyperbolic phase profiles at different optimized values of wavelength and focal length. The transverse and longitudinal positions of spin-dependent focal spots can be arbitrarily manipulated by adjusting the orientation angles of metal nanoholes. The intensities of the spin-dependent focal spots can be effectively controlled by the proportion of the phase profile associated with right- or left-hand circularly polarized component. In addition, our designed metalens enables the focusing beyond the optical diffraction limit across the above wavelength coverage as the phase profile only contains right or left-hand circularly polarized component. It is expected that our simple and novel metalens would be applied in polarimetric imaging, optical sensing, and photon spin splitting.