A silicon metasurface for full-Stokes polarimetry of infrared light

Polarimetry, refers to the measurement of polarization states, has triggered vital applications in polarization imaging, biological sensing, and quantum optics. Traditional polarimetry has been well established to characterize polarization states but with bulk optical elements. With the development of micro- and nano-optics, a polarimetry device with ultracompact architecture is highly on-demand. Herein, a silicon metasurface-based full-Stokes polarimetry device for long-wavelength infrared light is proposed and experimentally demonstrated. The metasurface is composed of silicon micropillar array, each of which can be regarded as a micro-scale birefringent wave-plate. Through a polarization-dependent phase profile design, the metasurface has the ability to split and focus different polarization states and, thus, is capable of achieving full-Stokes polarimetry. The demonstrated strategy holds the potential applications for infrared polarization detection and imaging in compact systems.