Time-dependent spectra of a three-level atom in the presence of electron shelving

TL;DR

This paper analyzes the time-dependent resonance fluorescence spectra of a three-level atom with electron shelving, revealing the emergence of spectral features during different decay regimes and their relation to the atom's steady state.

Contribution

It provides a detailed analysis of the spectral evolution in a three-level atom with electron shelving, highlighting the timing of spectral feature emergence during decay.

Findings

Narrow incoherent peak appears during slow decay regime

Steady state spectrum includes coherent, incoherent Mollow-like, and narrow peaks

Coherent peak is absent during the transient evolution

Abstract

We investigate time-dependent spectra of the intermittent resonance fluorescence of a single, laser-driven, three-level atom due to electron shelving. After a quasi-stationary state of the strong transition, a slow decay due to shelving leads to the steady state of the three-level system. The long-term stationary spectrum consists of a coherent peak, an incoherent Mollow-like structure, and a very narrow incoherent peak at the laser frequency. We find that in the ensemble average dynamics the narrow peak emerges during the slow decay regime, after the Mollow spectrum has stabilized, but well before an average dark time has passed. The coherent peak, being a steady state feature, is absent during the time evolution of the spectrum