Super-resolved multispectral lensless microscopy via angle-tilted, wavelength-multiplexed ptychographic modulation

TL;DR

This paper introduces a novel multispectral lensless microscopy technique that uses angle-tilted, wavelength-multiplexed ptychographic modulation to achieve high-resolution, quantitative imaging of tissue samples on a compact on-chip platform.

Contribution

The authors develop a new approach combining spectral dispersion and ptychography to enable super-resolved, multispectral imaging with simple hardware modifications.

Findings

Achieved 0.55 micron half-pitch resolution.

Successfully reconstructed multispectral images of stained tissue sections.

Demonstrated high-quality, quantitative multispectral imaging for pathology.

Abstract

We report an angle-tilted, wavelength-multiplexed ptychographic modulation approach for multispectral lensless on-chip microscopy. In this approach, we illuminate the specimen with lights at 5 wavelengths simultaneously. A prism is added at the illumination path for spectral dispersion. Lightwaves at different wavelengths, thus, hit the specimen at slightly different incident angles, breaking the ambiguities in mixed state ptychographic reconstruction. At the detection path, we place a thin diffuser in-between the specimen and the monochromatic image sensor for encoding the spectral information into 2D intensity measurements. By scanning the sample to different x-y positions, we acquire a sequence of monochromatic images for reconstructing the 5 complex object profiles at the 5 wavelengths. An up-sampling procedure is integrated into the recovery process to bypass the resolution limit imposed by the imager pixel size. We demonstrate a half-pitch resolution of 0.55 microns using an image sensor with 1.85-micron pixel size. We also demonstrate quantitative and high-quality multispectral reconstructions of stained tissue sections for digital pathology applications.