Phase Measurement, Analysis, and Correction Methods for Coherent Imaging Systems

摘要

Methods and apparatus for assessing and correcting phase variations and motion artifacts in a coherent tomogram of a sample. Coherent techniques are used scan a broadband optical beam across a sample in a specified scan pattern and to acquire a cube of complex data constituting a full tomogram. Generalized motion of the sample is then quantified based at least on a phase variation measured during the course of scanning the broadband optical beam in the specified scan pattern. Generalized motion includes both actual motion and apparent motion due to organized variation of some physical parameter such as temperature. Intensity structure of speckle imaged during the course of coherently acquiring the full tomograpm may be used to correct for motion of the sample in a plane transverse to a depth axis along the incident beam.

主权项

1. A method for measuring phase variations in a coherent three-dimensional image of a sample, the method comprising:
a. generating a broadband optical beam incident on the sample along a depth axis; b. scanning the broadband optical beam across the sample in a specified scan pattern; c. interfering light scattered by the sample with a reference beam derived from the broadband optical beam; d. measuring the intensity of the interfered light on at least one photosensitive element; e. processing the collected data to generate a cube of complex data including both amplitude and phase data constituting a full tomogram; and f. after acquisition of the full tomogram, quantifying generalized motion to the sample based at least on a measured phase variation measured during the course of scanning the broadband optical beam in the specified scan pattern, wherein the phase variation is measured based solely on a frame of reference tied to the sample.