Fig. 2: The operational principle of the nanophotonic polarization camera consists of three steps: calibration, capture, and reconstruction.
a Schematic of the calibration process. ➀ denotes a narrowband spectral filter. ➁ denotes an imaging lens. b The responsivity matrix \({{{{{\boldsymbol{R}}}}}}\) of the whole meta-device is calibrated from the photoresponses to the three pairs of orthogonal SoPs of incident light. c Schematic of the capture process. Scattered optical waves at each position (x, y) of target scene represented an unknown SoP \({{{{{\boldsymbol{S}}}}}}={\left[{S}_{0},{S}_{1},{S}_{2},{S}_{3}\right]}^{T}\), illuminates the imaging system. d A single-shot capture process generates the polarization-encoded image I. e Mathematical description of the relation between \({{{{{{\boldsymbol{S}}}}}}}_{{{{{{\boldsymbol{v}}}}}}}\), Iv, and \({{{{{\boldsymbol{\Lambda }}}}}}\). f SoP reconstruction by the convolutional neural network. g Reconstructed SoP and corresponding position on Poincaré sphere.
