A self-locked magneto-optic trap

Abstract

We present a novel technique to lock the frequency of the trapping laser of a magneto-optic trap (MOT) using a signal generated from the ultracold atoms in the MOT itself. This technique utilizes the large number of very cold, slow-moving atoms in the MOT to generate a signal free of Doppler-broadening. A system analogous to Pound–Drever–Hall locking allows an error signal to be generated on resonance without significantly perturbing the MOT. We have successfully stabilized the frequency of the main trapping laser of a 87Rb MOT using this technique to generate a self-locked MOT.