Abstract

We report a new method by which phase slope and group dispersion can be calculated with a simple optical low-coherence reflectometer to quantify physiological conditions. A discrete-time signal processing algorithm based on the first and second derivatives of the phase with respect to wave number was developed from discrete-time Fourier properties. The algorithm avoids the 2π ambiguity associated with most phase unwrapping. Experimental data collected by use of well-characterized optical materials validated the algorithm, which was minimally sensitive to phase noise. The group dispersion of bovine cornea was measured at various hydrations and was significantly dependent on hydration. The results suggest that group dispersion is an indicator of corneal alterations.

© 2003 Optical Society of America

Group index of the human cornea at 1.3-µm wavelength obtained in vitro by optical coherence domain reflectometry

Roger C. Lin, Mark A. Shure, Andrew M. Rollins, Joseph A. Izatt, and David Huang
Opt. Lett. 29(1) 83-85 (2004)

Phase-sensitive optical low-coherence reflectometry for the detection of analyte concentrations

Kirill V. Larin, Taner Akkin, Rinat O. Esenaliev, Massoud Motamedi, and Thomas E. Milner
Appl. Opt. 43(17) 3408-3414 (2004)

Measurement and imaging of water concentration in human cornea with differential absorption optical coherence tomography

Michael Pircher, Erich Götzinger, Rainer Leitgeb, Adolf F. Fercher, and Christoph K. Hitzenberger
Opt. Express 11(18) 2190-2197 (2003)

Autofocus algorithm for dispersion correction in optical coherence tomography

Daniel L. Marks, Amy L. Oldenburg, J. Joshua Reynolds, and Stephen A. Boppart
Appl. Opt. 42(16) 3038-3046 (2003)

Dispersion in a grating-based optical delay line for optical coherence tomography

Walter K. Niblack, John Otto Schenk, Bin Liu, and Mark E. Brezinski
Appl. Opt. 42(19) 4115-4118 (2003)