Abstract

The utilisation of phase/frequency modulated optical fields can significantly influence light-matter interactions e.g. it has been demonstrated experimentally that phase/frequency modulation increases optical forces exerted on atoms [1]. Recently, there has been significant theoretical and experimental interest in light-matter interactions and instabilities which can occur when many cold atoms interact collectively or cooperatively with a common optical field . Experiments carried out by the Zimmermann group in Tubingen demonstrated Collective Atomic Recoil Lasing, (CARL)[2], where atoms in a unidirectionally pumped ring cavity spontaneously undergo a transition from a disordered state, where the atomic positions are essentially random, to an ordered state where the atoms form a dynamic, spatially periodic density grating which backscatters the pump field[3,4]. It has been shown recently that the effect of a phase-modulated pump beam on the CARL instability involving a classical cold gas can give rise to three different dynamical regimes depending on the frequency of modulation [5,6] and that for certain values of modulation frequency the atomic dynamics is chaotic.

© 2011 IEEE