Effects of twin-beam “squashed” light on a three-level atom

Abstract

An electro-optical feedback loop can make in-loop light (squashed light) which produces a photocurrent with noise below the standard quantum limit (like squeezed light). We investigate the effect of squashed light interacting with a three-level atom in the cascade configuration and compare it to the effects produced by squeezed light and classical noise. It turns out that one master equation can be formulated for all three types of light and that this unified formalism can also be applied to the evolution of a two-level atom. We show that squashed light does not mimic all aspects of squeezed light, and in particular it does not produce the characteristic linear intensity dependence of the population of the upper-most level of the cascade three-level atom. Nevertheless, it has non-classical transient effects in the de-excitation. 42.50.Dv, 42.50.Ct,

Squeezing and Feedback

“…I would like to thank Laura Thomsen for a careful reading of this manuscript. In work subsequent to the completion of this manuscript, we have generalized the work described above by considering the effect of twin-beam squashed light on a three-level atom [66]. We have also shown how feedback can be used to prepare near-minimum uncertainty spin-squeezed states [67].…”

Effect of biased noise fluctuations on the output radiation of coherent beat laser

“…In the present day state of the art technology, biased noise fluctuations can be generated, for instance, by optical feedback loop [17]. In light of this, the effects of the biased noise fluctuations (squashed light and twin beams) on the radiative properties of a three-level cascade atom have been discussed by Wiseman and co-worker [18][19][20] earlier.…”