A method for independent and continuous tuning of $N$ lasers phase-locked to the same frequency comb

摘要

We present a method of phase-locking any number of continuous-wave lasers toan optical frequency comb (OFC) that enables independent frequency positioningand control of each laser while still maintaining lock to the OFC. The schemeemploys an acousto-optic modulator (AOM) in a double pass configuration addedto each laser before its light is compared by optical heterodyne with the comb.The only requirement is that the tuning bandwidth of the double pass AOM setupbe larger than half the OFC repetition rate. We demonstrate this scheme andachieve an arbitrary frequency tuning precision, a tuning rate of 200~MHz/s anda readout precision at the 1~kHz level.