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.