Systems and methods for surface profile estimation via optical coherence tomography

A method for profilometry measurements of a specimen in an optical coherence tomography (OCT) system, the method comprising:

• splitting by an interferometer, incident light into a reference beam and a test beam, and interfering the test beam reflected from the specimen with the reference beam reflected from a reference mirror to produce an interference pattern;
• analyzing by a spectrometer, spectral components of the interference pattern at non-uniformly sampled wavenumbers;
• wherein a computer-readable memory of the OCT system stores 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
• determining 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.

A non-transitory computer readable medium having stored thereon computer-executable instructions which when executed by a computer, causes the computer to perform a method for profilometry measurements of a specimen in an optical coherence tomography (OCT) system, the method comprising:

• splitting by an interferometer, incident light into a reference beam and a test beam, and interfering the test beam reflected from the specimen with the reference beam reflected from a reference mirror to produce an interference pattern;
• analyzing by a spectrometer, spectral components of the interference pattern at non-uniformly sampled wavenumbers;
• wherein a computer-readable memory of the OCT system stores 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
• determining 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.