Patent ID: 8077325

Claim:
A method of identifying variations in the index of refraction of a sample, the method comprising: propagating a sample beam of a broadband interferometer through the sample; obtaining a plurality of broadband interferometric complex optical profiles of a portion of the sample as a function of sample depth in an axial direction, each of the pluraliaty of broadband interferometric complex optical profiles comprising a reference signal propagated through a reference path and reflected from a reference reflector and a sample signal propagated through a sample path to the sample and reflected from a sample reflector, wherein the interferometric complex optical profiles include magnitude data and phase data as a function of depth; determining phase variations between the phase data of the plurality of interferometric complex optical profiles evaluated at the path length difference between the sample and reference paths at a selected axial position; and identifying variations in an index of refraction of the sample based on the phase variations of the phase data at the selected axial position.