Laser ranging with analog all-optical coherent pulse compression

Abstract

We propose and demonstrate a simple experimental platform that enables ranging by optical coherent pulse compression. Our system, based on a frequency shifting loop, is particularly simple and involves only a single CW laser and standard telecom components. It does not require fast electronic systems, since the pulse compression is realized in a purely analog way, by the beating between two sequences of optical chirped waveforms with the same chirp rate, but slightly different repetition rates. We demonstrate a range resolution in the centimeter range set by the bandwidth of the optical chirps, 24 GHz, and a time-bandwidth product of 300, with a detection bandwidth of only a few tens of MHz.