Spectroscopy in frequency, time, and position with correlated frequency combs

A system comprising:

• a single laser source having a laser cavity, the single laser source structured to generate a first beam and a second beam within the laser cavity and output the first beam and the second beam from the single laser source, the first beam in frequency domain being a first frequency comb and the second beam in frequency domain being a second frequency comb, with a repetition rate of each of the first and second frequency combs being equal and with the first and second frequency combs shifted in frequency from each other;
• a delay structure arranged to operatively delay the first beam, the first beam being a reference beam;
• and
• a spectrometer to receive the reference beam directed from the delay structure and to receive a signal beam from a sample, the signal beam being a version of the second beam after interaction of the second beam with the sample, with the spectrometer arranged such that operationally the reference beam from the delay structure interferes with the signal beam from the sample.