Experimental observation of strong light-matter coupling in ZnO microcavities: influence of large excitonic absorption

TL;DR

This paper reports the experimental observation of strong light-matter coupling in ZnO microcavities, demonstrating significant Rabi splitting and the influence of excitonic absorption on the coupling regime.

Contribution

It provides new experimental evidence of strong coupling in ZnO microcavities with low finesse and analyzes the role of excitonic absorption through both experiments and simulations.

Findings

Rabi splittings of about 70 meV achieved

Strong coupling observed even in low finesse cavities

Large excitonic absorption influences the coupling behavior

Abstract

We present experimental observation of the strong light-matter coupling regime in ZnO bulk microcavities grown on silicon. Angle resolved reflectivity measurements, corroborated by transfer-matrix simulations, show that Rabi splittings in the order of 70 meV are achieved even for low finesse cavities. The impact of the large excitonic absorption, which enables a ZnO bulk-like behavior to be observed even in the strong coupling regime, is illustrated both experimentally and theoretically by considering cavities with increasing thickness.