Metasurface differential optics: from classical to quantum

Metasurface differential optics represents a transformative paradigm that bridges classical wavefront manipulation and quantum information processing. By leveraging subwavelength nanostructure to precisely control light’s phase, amplitude, and polarization, metasurfaces enable compact, efficient, and intelligent optical analog computing. The theoretical framework for implementing differential operations using metasurfaces based on the Pancharatnam-Berry (PB) phase has been rigorously derived. Building upon this foundation, we have developed a differential interference theory and elucidated its profound significance in precision measurement and imaging applications. In the classical domain, differential metasurfaces perform real-time spatial operations such as edge detection, chiral sensing, surface characterization, and quantitative phase imaging. Beyond miniaturization, these surfaces have evolved into sophisticated tools for differential interference contrast microscopy and vectorial imaging, offering high contrast and label-free visualization of transparent specimens. The convergence of differential metasurfaces with quantum optics marks a revolutionary leap. By integrating with quantum light sources, metasurfaces facilitate nonlocal sensing, quantum edge detection, phase distillation under strong noise, and high-SNR quantitative phase reconstruction. This synergy amplifies the computational power of metasurfaces through quantum entanglement and correlations, opening new avenues in quantum sensing, imaging, and information processing. Overall, metasurface differential optics is not merely an advancement in photonics but a foundational platform that seamlessly merges classical optical engineering with quantum technology, promising profound impacts across biomedical diagnostics, machine vision, and future quantum hardware.