A scheme comparison of Autler-Townes based slow light in inhomogeneously broadened quantum dot media

TL;DR

This paper compares three Autler-Townes based schemes in inhomogeneously broadened quantum dot media to achieve optical signal delays, finding the V-scheme offers larger delays despite absorption, with implications for waveguide applications.

Contribution

The study provides a comparative analysis of three excitation schemes, revealing the unique advantages of the V-scheme for slow light in quantum dot media.

Findings

V-scheme shows distinct Autler-Townes features

V-scheme achieves larger signal delays

Waveguide structures can enhance delays

Abstract

We propose a method to achieve significant optical signal delays exploiting the effect of Autler-Townes splitting in an inhomogeneously broadened quantum dot medium. The absorption and slow-down effects are compared for three schemes i.e. $\Xi$, V and $\Lambda$, corresponding to different excitation configurations. Qualitative differences of the V-scheme compared to the $\Xi$- and $\Lambda$-scheme are found, which show that features of Autler-Townes splitting are only revealed in the V-scheme. The underlying physical mechanisms causing this discrepancy are analyzed and discussed. Finally we compare field propagation calculations of the schemes showing significantly larger achievable signal delays for the V-scheme despite finite absorption of the coupling field. This opens the possibility for using waveguide structures for both coupling and probe fields, thus significantly increasing the achievable signal delays.