Needle-based reflection refractometry of scattering samples using coherence-gated detection.
We present a novel method for in situ refractive index measurement of scattering samples using a needle device. The device employs a fiber-based reflectance refractometer and coherence-gated detection of the reflected optical signal that eliminates scattering-dependent backreflection contributions. Additionally, birefringence changes induced by fiber movement are neutralized by randomizing the source polarizations and averaging the measured Fresnel reflection coefficients over many incident polarization states. Experimental measurements of Intralipid scattering solutions are presented and compared with Monte Carlo simulations.
Zysk
Adam M
AM
Biophotonics Imaging Laboratory, Beckman Institute for Advanced Science and Technology, Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, 405 North Mathews Avenue, Urbana, IL 61801, USA
Marks
Daniel L
DL
Liu
Dianna Y
DY
Boppart
Stephen A
SA