M. Sticker et al., Quantitative differential phase measurement and imaging in transparent andturbid media by optical coherence tomography, OPTICS LETT, 26(8), 2001, pp. 518-520
Differential phase-contrast optical coherence tomography allows one to meas
ure the path-length differences of two transversally separated beams in the
nanometer range. We calculate these path-length differences ti-om the phas
e functions of the interferometric signals. Pure phase objects consisting o
f chromium layers containing steps of approximately 100-200-nm height were
imaged. Phase differences can be measured with a precision of +/-2 degrees,
corresponding to a path-difference resolution of 2-3 nm. To investigate th
e influence of scattering, we imaged the phase objects through scattering l
ayers with increasing scattering coefficients. The limit of phase imaging t
hrough these layers was at approximately 8-9 mean free path lengths thick (
single pass). (C) 2001 Optical Society of America.