Theory of Exciton Spontaneous Emission in Semiconductor Mesoscopic Quantum Disks Embedded in a Planar Microcavity

We theoretically discuss the exciton spontaneous emission dynamics in mesoscopic quantum disks placed in an ideal planar microcavity. The disks approach macroscopic quantum wells as the disk diameter increases above the exciton resonant wavelength and approach microscopic quantum dots as the disk radius decreases below the exciton Bohr radius. We present formulae for exciton spontaneous emission, regardless of the disk radius and the exciton-photon coupling strength. By numerical calculations, we show continuous transition from the exponential decay in the weak-coupling regime to the oscillatory behavior due to the exciton-radiation field energy exchange in the strong-coupling regime. We clarify how the oscillatory behavior and emission spectra vary with the photon decay rate, the exciton dissipation time, exciton-cavity mode detuning, and the disk radius.