Patent ID: 11860087
Assignee: THE BOARD OF TRUSTEES OF THE UNIVERSITY OF ILLINOIS
Field: Measurement (Instruments)
Classification: CPC G | IPC G

Claim 7:
8. The method of claim 6, further comprising:
inserting, into the sample, a fiducial of known geometry that absorbs infrared light at a third wavelength that differs from the first wavelength, wherein a remainder of the sample is substantially does not absorb infrared light at the third wavelength;
subsequent to inserting the fiducial into the sample, generating a third plurality of sets of probe measurements for the plurality of sample locations located across the surface of the sample, wherein generating, for a particular sample location, a particular set of probe measurements of the third plurality of sets of probe measurements comprises:
generating a first probe measurement of the particular set of probe measurements by illuminating the sample with infrared light at the third wavelength that varies at the first frequency and measuring a magnitude and phase of a variation in displacement of the surface of the sample over time at the particular sample location at the first frequency; and
generating a second probe measurement of the particular set of probe measurements by illuminating the sample with infrared light at the third wavelength that varies at the second frequency and measuring a magnitude and phase of a variation in displacement of the surface of the sample over time at the particular sample location at the second frequency, wherein the first frequency and the second frequency differ; and

generating the first thermoelastic Green's function and the second thermoelastic Green's function based on the third plurality of sets of probe measurements.