US 12,336,785 B2
Systems and methods for surface profile estimation via optical coherence tomography
Joshua Rapp, Somerville, MA (US); Hassan Mansour, Boston, AL (US); Petros Boufounos, Winchester, AL (US); Philip Orlik, Cambridge, MA (US); Toshiaki Koike Akino, Cambridge, AL (US); and Kieran Parsons, Cambridge, MA (US)
Assigned to Mitsubishi Electric Research Laboratories, Inc., Cambridge, MA (US)
Filed by Mitsubishi Electric Research Laboratories, Inc., Cambridge, MA (US)
Filed on Sep. 14, 2022, as Appl. No. 17/932,215.
Prior Publication US 2024/0090768 A1, Mar. 21, 2024
Int. Cl. A61B 5/00 (2006.01); G01B 9/02 (2022.01); G01B 9/0209 (2022.01); G01B 9/02091 (2022.01)
CPC A61B 5/0066 (2013.01) [G01B 9/02088 (2013.01); G01B 9/0209 (2013.01); G01B 9/02091 (2013.01); G01B 9/02044 (2013.01)] 20 Claims
OG exemplary drawing
 
1. An optical coherence tomography (OCT) system for profilometry measurements of a specimen, comprising:
an interferometer configured to split incident light into a reference beam and a test beam, and to interfere the test beam reflected from the specimen with the reference beam reflected from a reference mirror to produce an interference pattern;
a spectrometer configured to analyze spectral components of the interference pattern at non-uniformly sampled wavenumbers;
a computer-readable memory configured to store a measurement model with elements connecting different depth values with different non-uniformly sampled wavenumbers and weighted with weights derived from a power spectral density (PSD) of the incident light for corresponding wavenumbers; and
a processor configured to determine the profilometry measurements of the specimen as a maximum likelihood estimate of the specimen surface depth by back-projection of measured intensities of the interference pattern with the measurement model.