Optical emission of InAs/GaAs quantum rings coupled to a two-dimensional photonic crystal microcavity

Microphotoluminescence measurements on InAs/GaAs quantum rings embedded in a bi-dimensional photonic crystal cavity display enhanced emission intensity of single rings depending on the coupling strength to the cavity modes. The cavity is formed by three holes missing at the center of the photonic crystal structure (a linear 3 defect, L3). Light emission by the quantum rings show sharp lines at low excitation power. They undergo different enhancement factors by the separate effects of the photonic crystal and by coupling to the resonant modes, which show full linear polarization. Upon changing temperature, the uncoupled emission of single quantum rings and the resonant modes undergo different frequency shifts. This allows for an external control of the coupling.