Exciton-light coupling in cylindrical microcavities

A quantum treatment of exciton-polaritons which are formed when a quantum w ell is embedded in a cylindrical microcavity is developed. Leakage of the p hoton modes in air reduces the Rabi splitting with respect to the planar ca vity case. The two oscillator model does not describe anymore the exciton-c avity mode interaction, since lack of in-plane translational invariance is responsible for the coupling of the exciton with a great number of photon m odes. Only at very large radii the two-oscillator model is recovered; moreo ver, in this limit the Rabi splitting tends to the same value as that attai ned in a planar microcavity.