Full-Field Metasurface Characterization with Polarization Sensitive Coherent Modulation Imaging

TL;DR

This paper introduces PS-CMI, a compact and high-resolution technique for full-field characterization of metasurface-modulated light, including intensity, phase, and polarization, overcoming previous limitations in polarization measurement.

Contribution

The paper presents a novel polarization sensitive coherent modulation imaging method that accurately measures the complete polarization state of light fields modulated by metasurfaces.

Findings

Successfully characterized complex polarization fields and a metalens.

Demonstrated high-resolution, full-field measurement capabilities.

Addressed a critical gap in metasurface metrology.

Abstract

Characterizing the intensity, phase, and polarization of engineered light is fundamental to understanding and applying metasurfaces. However, existing characterization frameworks are hindered by several limitations, most notably their inability to account for the polarization of the field. Here, we report polarization sensitive coherent modulation imaging (PS-CMI), a light-weight but robust, high-resolution platform for the full-field characterization of metasurface-modulated light. By supplementing the orthogonal x- and y- complex amplitude components with an additional 45{\deg}-component, this approach calculates the retardance between two orthogonal polarization components while eliminating phase offsets, thereby enabling the subsequent recovery of the complete polarization state. We demonstrate the versatility of our method by characterizing light fields produced by a United States Air Force (USAF) target, two kinds of complex polarization field, and a metalens. This compact solution addresses a critical gap in metasurface metrology and is broadly applicable to other fields requiring the mapping of complex, polarized light distributions.