Shearing interferometric fluorescence tomography for depth and spectrally resolved volumetric imaging

Abstract

We introduce shearing interferometric fluorescence tomography (SIFT), a novel imaging technique that uses self-interference of fluorescent wavefronts to achieve axial localization of fluorophores. A shearing interferometer encodes wavefront curvature within spatial frequencies that vary with origin-fluorophore depth. This depth-multiplexed approach enables simultaneous acquisition of the entire axial fluorescence profile at each lateral excitation point. We present theory and experimental validation demonstrating axial sectioning and the feasibility of volumetric spectroscopic fluorescence imaging using SIFT. The depth-multiplexing capability of SIFT enables high-speed z-stack acquisition, with potential to improve fluorescent imaging for the study of degenerative retinal diseases and regenerative therapies.