Device Designing Of Imaging Polarimetry With Wide Field Metasurfaces

Polarization imaging techniques can acquire light intensity information and polarization information of the target.From astronomy and remote sensing to the biological identification of marine biology and medicine,polarization imaging technology provides the polarization dimension information for scientific research to enhance the surface characteristics of the sample,protruding the shape,texture,roughness of the sample,providing a convenient measurement method for some polarization-related physical mechanisms.At present,the Pixelated-Polarization Camera is unable to detect the circular polarization component of the beam,and the assembly difficulty of the lens group and the grating is large,so many polarized imaging techniques that integrated the Stokes vector measurement and the lens imaging into single-chip,based on metasurfaces have occurred.This way can achieve measuring for the Stokes vector avoiding the cumbersome assembly of lens and polarizer,and the miniaturization feature of the metasurfaces device is advantageous for the integration of optical systems which makes the metasurfaces polarization imaging have better adaptability.However,the current metalens faces a small angle of view and the terrible coma.Therefore,this article design polarization measurement for off-axis samples.To achieve polarization imaging of the off-axis sample,the secondary phase distribution is used to realize the focus function of the metasurfaces to the off-axis point.According to coordinate transformation relation between the oblique polarized incident light and the metasurfaces interface,we calculate the polarization change of obliquely polarized incident light.A pair of nanofins within a half wavelength construct a supercell.According to the effective medium theory and the widely Snell’s Law,for sub-wavelength sized supercell,the amplitude and the phase distribution of the transmissive polarization light is uniform,the orthogonal polarization light is converted from the transmission wave into a pulverized wave.The selection of polarization is achieved.This article scans the nanofins parameters according to the design of the metasurfaces,establishing the ‘artificial atom’ library.According to generates the machining map of the metasurfaces,we inlaid photolithography sample.After obtaining a large-view metasurfaces polarization imaging device,the subject proven that the metasurfaces device had a pair of polarization of the axis and off-axis polarization imaging function with the simulation and experiment.By reflecting light of different material samples,the polarization imaging of the sample in the large vision angle is achieved.The wide field polarization imaging metasurfaces device in this article design can achieve polarization imaging in wide field view.Meanwhile,axis focus and off-axis focus is located at the focal plane.When measuring the sample,the polarization imaging can not be limited to the axis condition,weakened the relative positional relationship of the optical axis of the sample and the optical system,and reduced the calibration difficulty of the polarization imaging metasurfaces device,which is advantageous for the integration of polarization imaging metasurfaces.