Luminescence enhancement by Si ring resonator structures on silicon on insulator

Si ring resonators on silicon on insulator show at least 50 times stronger photoluminescence (PL) with sharp peaks than the surrounding Si slab region at room temperature. The frequencies of the PL peaks are well explained by the resonant frequencies of the rings and the intensities are by the ratio of the quality factors of the PL peaks and the modal volumes of resonances. This suggests that the Purcell effect should be responsible for the enhancement.