Fourier-domain low-coherence interferometry for light-scattering spectroscopy.
We present a novel method for obtaining depth-resolved spectra for determining scatterer size through elastic-scattering properties. Depth resolution is achieved with a white-light source in a Michelson interferometer with the mixed signal and reference fields dispersed by a spectrograph. The spectrum is Fourier transformed to yield the axial spatial cross correlation between the signal and reference fields with near 1-microm depth resolution. Spectral information is obtained by windowing to yield the scattering amplitude as a function of wave number. The technique is demonstrated by determination of the size of polystyrene microspheres in a subsurface layer with subwavelength accuracy. Application of the technique to probing the size of cell nuclei in living epithelial tissues is discussed.
Wax
Adam
A
Department of Biomedical Engineering and the Fitzpatrick Center for Photonics, Duke University, Durham, North Carolina 27708, USA. a.wax@duke.edu
Yang
Changhuei
C
Izatt
Joseph A
JA
D005583:Fourier Analysis; D007368:Interferometry; D008027:Light; D008962:Models, Theoretical; D012542:Scattering, Radiation; D013057:Spectrum Analysis