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Journal of the Optical Society of America B

Journal of the Optical Society of America B


  • Vol. 9, Iss. 12 — Dec. 1, 1992
  • pp: 2163–2170

ac Stark shift of a two-photon transition induced by a model stochastic field

J. C. Camparo and P. P. Lambropoulos  »View Author Affiliations

JOSA B, Vol. 9, Issue 12, pp. 2163-2170 (1992)

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We have investigated the ac Stark shift of a two-photon transition induced by a model stochastic field by using a Monte Carlo technique. The model field has a stochastic single mode, which can possess both colored amplitude and colored frequency fluctuations. The stochastic field's modification of the ac Stark shift is quantified by a parameter <i>M</i>, which is the ratio of the Stark shift in the model stochastic field to the Stark shift that would be obtained in a phase-diffusion field of equivalent linewidth (i.e., a field with frequency fluctuations but no amplitude fluctuations). In the regime of weak fields, below saturation of the bound–bound transition, we find that <i>M</i> is greater than unity: the Stark shift is enhanced by the stochastic field. Moreover, in this regime <i>M</i> is an increasing function of the field's degree of photon bunching. In strong fields, where the bound–bound transition is nearly saturated, the enhancement of the Stark shift is diminished, so much so that in extremely strong fields <i>M</i> is actually less than unity. Our calculations indicate that the ac Stark shift's modification occurs through two distinct processes, depending on the strength of the field. In weak fields enhancement of a multiphoton transition's Stark shift is influenced primarily by the intrinsic correlation between ac-Stark-shift fluctuations and Rabi-frequency fluctuations. In strong fields the fluctuating Stark shifts give rise to an asymmetric resonance line shape in a fashion analogous to inhomogeneous broadening. The line shape's peak position then has a sublinear dependence on the stochastic field's intensity, and this yields a diminished value of <i>M</i>.

© 1992 Optical Society of America

J. C. Camparo and P. P. Lambropoulos, "ac Stark shift of a two-photon transition induced by a model stochastic field," J. Opt. Soc. Am. B 9, 2163-2170 (1992)

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  27. Actually, this procedure is repeated twice: once for a positive value of Κ and once for a negative value of Κ. These two ac Stark shifts are then averaged in order to account for the stochastic realization shift, as discussed in Ref. 28.
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  34. A. T. Georges and P. Lambropoulos, "Saturation and stark splitting of an atomic transition in a stochastic field," Phys. Rev. A 20, 991 (1979).

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