First-order coherence of light emission from inhomogeneously broadened mesoscopic ensembles

Inhomogeneous broadening is well known to hinder individual characteristics of emitters, supplanting the single-particle properties by their broader probability distribution. Here, we present an analysis emission spectra mesoscopic ensembles inhomogeneously distributed emitters below thermodynamic limit (10 - 10^4 emitters). Based on a simple analytical model and extensive numerical analysis, show that number linewidths can be directly estimated from ensemble autocorrelation function in spite broadened emission. As application, analyze photoluminescence colloidal nanocrystal aggregates embedded gold shell. Our general method applied wide range many-body systems could provide new insights into first-order coherence properties.