Programmable spatial coherence tomography: diffraction-limited three-dimensional reflection imaging under modulated monochromatic illumination

TL;DR

Programmable spatial coherence tomography (PSCT) enables diffraction-limited 3D reflection imaging using spatial coherence engineering, eliminating the need for temporal coherence gating in complex biological samples.

Contribution

This work introduces PSCT, a novel method that uses pupil-coded illumination patterns for self-calibration and high-resolution volumetric imaging without guide stars.

Findings

Achieved label-free 3D imaging of thick tissues and organoids.

Demonstrated in vivo brain imaging through a cranial window.

Enabled dynamic contrast imaging with frequency resolution.

Abstract

Depth sectioning in reflection microscopy has predominantly relied on temporal coherence gating. Here we show that volumetric reflection tomography at diffraction-limited resolution can be achieved under monochromatic illumination by engineering spatial, rather than temporal, coherence. In programmable spatial coherence tomography (PSCT), a sequence of pupil-coded illumination patterns with angular-spectrum diversity generates measurement redundancy enabling the system to calibrate itself, jointly retrieving aberrations, illumination profiles, and sample motion without guide stars or modal priors. We demonstrate label-free volumetric imaging of thick human tissues, organoids, frequency-resolved dynamic contrast, and high-resolution in vivo brain imaging through a cranial window. These results position PSCT as an alternative to temporal coherence based reflection imaging in complex biological systems.