Spectral domain fluorescence coherence phase microscopy.

Spectral domain phase microscopy (SDPM) has been reported in the literature as a functional extension to low-coherence interferometry, which enables nanoscale measurement of a scatter's displacement. The signal in SDPM is generated from structural images that lack molecular specificity. This paper investigates the expansion of phase analysis to fluorescence self-interference signals to provide functional information about a sample. Spectral domain fluorescence coherence phase microscopy is demonstrated for nanoscale resolution motion detection of fluorescent particles with a signal-to-noise ratio limited resolution of ~10 nm. This paper demonstrates the feasibility of combining phase processing with fluorescence self-interference, which may be useful for future applications such as cell rheology.