Shearing interferometric fluorescence tomography (SIFT) for depth- and spectrally-resolved volumetric imaging

We introduce shearing interferometric fluorescence tomography (SIFT), which utilizes self-interference of fluorescence emission wavefronts to axially localize fluorophores in depth. Our proposed method uses shearing interferometer to encode wavefront curvature as spatial frequencies, decoupling axial resolution from lateral. A depth-multiplexed approach is described that includes simultaneous acquisition of entire depth fluorescence profile at each excitation location. We present theory and experimental validation displaying axial sectioning and verifying potential application of SIFT for volumetric spectroscopic fluorescence imaging. Depth-multiplexing can enable high-speed z-stack imaging and provides broad potential applications in in vitro and in vivo imaging in basic science and clinical diagnostics.