Polarimetric imaging, as a novel optical imaging technique, is widely used in fields such as biomedicine, object recognition, polarimetric remote sensing, and 3D imaging. In the field of biomedicine, polarimetric imaging has two unique advantages compared to traditional optical imaging: 1) By analyzing the polarization properties of light interacting with biospecimens, microscopic-level information about the composition and structure can be obtained without requiring labeling agents. For example, collagen fibers in connective tissues can alter the polarization state of light passing through them. Measuring this alteration provides information about collagen fiber orientation and density, which are associated with various diseases such as cancer and fibrosis. 2) By selectively filtering out light waves with certain polarization states, it is possible to enhance image contrast and improve the visibility of certain structures or components based on the birefringence maps.

Ideal optical imaging relies upon the high-quality focusing of excitation light and accurate detection of the emission light from the fluorescent sample. However, both the optics in the microscope and the biological samples being investigated can introduce aberrations, thus causing degradation in resolution, loss of fluorescent photons, and deterioration of signal-to-background-ratio (SBR), etc. Moreover, microscopes with high numerical apertures (NA), especially the super-resolution microscopy, are more sensitive to aberrations, because the high-NA objectives are more susceptible to high-order aberrations. To detect and correct these optical aberrations, a large number of adaptive optics (AO) technologies have been explored in the last two decades. Conventional AO leverages specific devices, such as the Shack-Hartmann wavefront sensor to measure and correct optical aberrations, then utilized wavefront corrective devices such as spatial light modulators (SLMs) to compensate for the measured aberrations by reshaping the wavefronts. However, conventional AO complicates the optics, imaging procedures, and computation, resulting in many limitations in the actual imaging process.

Vortex is one of the most common phenomena in nature. In 1992, Allen et al. proposed that such vortex beams carry orbital angular momentum (OAM), which has furthered the development of vortex beams in various fields, including optical tweezer, quantum communication and bio-image.

Metasurfaces, which consist of tailor-made two-dimensional arrays of resonant structures, are promising for achieving planar and compact optical devices capable of shaping optical waves. Their performance is based on the design of the scattering phase of the individual resonant structures. While a variety of functions, such as optical vortex generation or focusing, have been reported separately, finding designs allowing the integration of multiple functions on a single metasurface is needed. This will further stimulate the development of metasurfaces for practical applications in high-speed data communication.