Optical frequency-domain ranging using a frequency-shifted feedback distributed-feedback laser

A distributed-feedback (DFB) laser is used in a frequency-shifted external cavity configuration to generate a frequency comb. The frequency comb generates a beat frequency in a Michelson interferometer, which is proportional to the path difference of a target and reference arm. The calculated and actual readings for the beat frequency are in good agreement. A proof of principle demonstration of using a DFB laser for optical frequency-domain ranging is shown for the first time.