An optical measurement system comprises an optical source configured for generating source light having an optical wavelength spectrum. The optical measurement system compises an interferometer configured for splitting the source light into sample light and reference light. The interferometer is further configured for delivering the sample light into an anatomical structure, such that the sample light is scattered by the anatomical structure, resulting in physiological-encoded signal light that exits the anatomical structure. The interferometer is further configured for combining the signal light and the reference light into interference light having the optical wavelength spectrum encoded with depths of the anatomical structure. The optical measurement system further comprises a dispersive spectrometer configured for generating an optical wavelength spectrum-intensity profile from the interference light. The optical measurement system further comprises a processor configured for determining a depth of a physiological event in the anatomical structure based on the optical wavelength spectrum-intensity profile.