IDEA #9DLTWJ Metasurface spectro-polarimeter 21A0010

Key Words: multifunctional metasurfaces, holography, optical characterization, spectrometry, polarimetry, spectropolarimetry. The invention provides a design process and experimental method for retrieving the spectrum and polarization properties of light collected within the device’s aperture. To be used in conjunction with a focal plane array (FPA), or other suitable camera sensor, the device and approach enables extraction of both the spectral content (how much optical energy is in each frequency) and the polarization state (Stokes parameters) at each frequency. The device (a ‘metasurface’) is a single, flat ultra-thin (thinner than 2 microns) surface composed of common dielectric materials (such as silicon, silicon dioxide, titanium dioxide). When placed in front of an FPA at a proper tilt angle, the device takes collimated light incident on the aperture of the device pass and holographically interferes it on the FPA plane. The metasurface is designed to scatter distinct wavelengths focused to distinct positions along the tilted axis (according to diffractive dispersion laws). For each wavelength, a number (>4) of focal spots in the orthogonal axis are encoded and produced by the device, with diffractive power correlated to the incident polarization state. After calibration, and by correlating optical power at each position with spectral and polarization content, the experimental method allows simultaneous retrieval of spectral and polarimetric data by simple processing of the 2D image produced on the FPA.