Strong Intensification of Parametric Fluorescence Due to the Confinement of Vacuum Field Fluctuations Inside Microcavities: Formalism without Resort to the Concept of Density of States
Serge Gauvin and Cory Walker
The behavior of excited atoms inside microcavities is bewildering and lead to various interpretations. We address this issue in relation with the density of states and the vacuum field fluctuations. Our model is somewhat different from previous ones; while not in contradiction. Our approach is based on the concept of modulation of the vacuum field fluctuations instead of the concept of density of states. This approach, based on the Fermi’s golden rule and the demonstration that electromagnetic confinement leads to an anomalous field commutation relation for field operators, preserves the original physical meaning of “mode” and “state”. Our point of view leads to the same conclusion about the intensification and inhibition of the transition rate without resort to the concept of density of states. To formally illustrate this finding, we present our end results in relation to parametric fluorescence (parametric down conversion, also known to be triggered by vacuum field fluctuations). It is shown that parametric fluorescence can be enhanced by orders of magnitude when it occurs in a suitable cavity. We finally suggest that parametric fluorescence might be a useful tool to probe any anomaly inside microcavities.
Keywords: Optical confinement, density of states, modulation of vacuum field fluctuations, spontaneous emission, “usual” and “parametric” fluorescence, nonlinear optics, surtension effect.