Nuclear morphology measurements using Fourier domain low-coherence interferometry

We have developed Fourier domain low coherence interferometry (fLCI), a novel optical interferometry method for obtaining depth-resolved spectral information, specifically for the purpose of determining the size of scatterers by measuring their elastic scattering properties. The optical system achieves depth resolution by using coherence gating, enabled by the use of a white light source in a Michelson interferometer and detection of the mixed signal and reference fields with a spectrograph. The measured spectrum is Fourier transformed to obtain the axial spatial cross-correlation between the signal and reference fields providing depth-resolution. The spectral dependence of scattering by the sample is determined by windowing the spectrum to measure the scattering amplitude as a function of wavenumber (k = 2 Pi / lambda, where lambda is the wavelength). We present a new common path confgiuration fLCI optical system and demonstrate its capabilities by presenting results which determine the size of cell nuclei in a monolayer of T84 epithelial cells.