Modelling of strong coupling regime in bulk GaN microcavities using transfer matrix and quasiparticle formalisms

The evolution of the polaritonic Rabi splitting versus the excitonic broadenings is analyzed within two different formalisms: the transfer-matrix and the quasiparticle models. The splittings are deduced from angle-resolved reflectivity measurements performed at 5 K and 300 K on two GaN microcavities grown on silicon. Although the quasiparticle model allows a qualitative analysis when the quality factor of the cavity is high, the transfer-matrix formalism is more appropriate for the interpretation of the reflectivity spectra, whatever the configuration of the structure.