An optical measurement system comprises an optical source assembly configured for intensity modulating sample light at multiple frequencies within a frequency range, and delivering the intensity modulated sample light along an optical path of an anatomical structure during a single measurement period, such that the intensity modulated sample light is scattered by the anatomical structure, resulting in signal light that exits the anatomical structure. The optical measurement system further comprises an optical detection assembly configured for detecting the signal light over the frequency range within the measurement period. The optical measurement system further comprises a processor configured for analyzing the detected signal light, and, based on this analysis, determining an occurrence and spatial depth of a physiological event in the anatomical structure.
