RESONANCE SHIFT DUE TO CORRELATED AMPLITUDE AND FREQUENCY VARIATIONS

Quite recently, Camparo and Lambropoulos predicted the existence of resonance frequency shifts due to a quantum system's dynamics in the presence of a fluctuating field. This shift is independent of any ac Stark or Bloch-Siegert effect, and is in part associated with the existence of cor-related amplitude and frequency fluctuations of the field. Here, we report experimental confirmation for a part of their predictions by showing that a field with correlated amplitude and frequency sinusoidal variations gives rise to a resonance frequency shift. Moreover, we show that in the regime of strong fields, this shift cannot be interpreted as a convolution of the fluctuating field's spectrum and the atomic resonance.