Advances in Metaoptics—From Snapshot Stokes Cameras to Mueller Matrix Metaimaging

Metasurfaces enable a new class of polarization components based on structural birefringence. The meta-atoms can be engineered to locally control the propagation phase and the geometric phase. Metasurfaces arranged in a grating in turn can be designed to implement in the far-field diffraction orders that represent specific polarization functionalities, designed using Matrix Fourier Optics, which are at the heart of new Stokes cameras with demonstrated greater performance than conventional ones, which suffer from either too many components, slow speed and other complexities. Our Stokes cameras involve a single metagrating, a focusing lens and the CMOS sensor, with advantages of detector limited speed, snapshot performance with all the Stokes parameters recorded at once, leading to superior imaging for a number of applications. When light scatters off an object, its polarization generally changes, a process described by the object's Mueller matrix. Mueller matrix imaging is a crucial technique in science and technology, used to image the spatially varying polarization response of an object and reveal information that traditional imaging cannot. We have conceptualized, implemented, and demonstrated a compact Mueller matrix imaging system. This system includes a metasurface for producing structured polarization illumination and another for polarization analysis, enabling it to capture all 16 components of an object's spatially varying Mueller matrix in a single shot. Our design, which avoids moving parts or bulky polarization optics, is expected to advance applications in real-time medical imaging, material characterization, machine vision, target detection, and other significant areas.<br/>The contributions of Noah Rubin, Aun Zaidi, Ahmed Dorrah, Joon Suh Park and Lisa Li and the financial support from AFOSR are gratefully acknowleded