Non-exponential spontaneous emission dynamics for emitters in a time-dependent optical cavity

TL;DR

This paper presents a theoretical study of controlling spontaneous emission in a dynamic optical microcavity, showing that rapid changes in the environment can produce non-exponential emission and photon bursts.

Contribution

It introduces a rate equation model for time-dependent spontaneous emission in microcavities, demonstrating non-exponential decay and photon bursts during cavity switching.

Findings

Short temporal increase in decay rate depletes excited states

Emission intensity peaks during cavity switching

Photon emission distribution deviates from exponential decay

Abstract

We have theoretically studied the effect of deterministic temporal control of spontaneous emission in a dynamic optical microcavity. We propose a new paradigm in light emission: we envision an ensemble of two-level emitters in an environment where the local density of optical states is modified on a time scale shorter than the decay time. A rate equation model is developed for the excited state population of two-level emitters in a time-dependent environment in the weak coupling regime in quantum electrodynamics. As a realistic experimental system, we consider emitters in a semiconductor microcavity that is switched by free-carrier excitation. We demonstrate that a short temporal increase of the radiative decay rate depletes the excited state and drastically increases the emission intensity during the switch time. The resulting time-dependent spontaneous emission shows a distribution of photon arrival times that strongly deviates from the usual exponential decay: A deterministic burst of photons is spontaneously emitted during the switch event.