Description
Quantitative phase imaging is the measurement of spatially varying phase distributions induced by scattering from a sample, permitting the observation of transparent objects and metrology. Conventional approaches to quantitative phase imaging systems typically involve bulky optical components and large propagation distances. The expanded functionality provided by metasurface optical components, called meta-optics, provide avenues for miniaturising such systems [1].
In this talk, we present different meta-optical realisations of quantitative phase imaging. In particular, we discuss metasurface filters with angle-dependent transmission that modify the Fourier components of an optical field. To obtain all the necessary information to recover the quantitative phase, multiple images with unique information content are required. To obtain such images efficiently, our metasurfaces employ multiplexing of distinct angle-dependent responses onto different degrees of freedom of light. Here we report on two strategies. In the first approach, a metasurface with multiplexed asymmetric transmission responses about normal incidence was achieved using photonic spin-orbit coupling into spectrally-selective guided mode resonances [2]. Circular polarisation multiplexing and wavelength multiplexing were employed to obtain phase gradient contrast along orthogonal directions which then entered into a noniterative phase retrieval algorithm to obtain the quantitative phase. In the second approach, a photonic crystal slab metasurface with dispersive polarisation-dependent Fano resonances was employed to generate polarisation-multiplexed multi-directional phase gradient contrast. Using oblique illumination with a broadband 750 nm LED as the light source, a polarisation-sensitive camera captures the necessary images for phase retrieval in a single shot. Recent results will be discussed.
[1] N. Priscilla, S. Sulejman, A. Roberts, and L. Wesemann, “New Avenues for Phase Imaging: Optical Metasurfaces,” ACS Photonics 11 (2024): 2843-2859, https://doi.org/10.1021/acsphotonics.4c00359.
[2] H. Wang, S. Ma, S. Sulejman, et al., “Wavelength and Polarization Multiplexed Nonlocal Metasurface for Quantitative Phase Microscopy,” Nanophotonics (2026): e70190, https://doi.org/10.1002/nap2.70190.
| I am the presenting author | Yes |
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