Enhanced light emission from Ge quantum dots in photonic crystal ring resonator

Light emitter based on Ge quantum dots embedded in photonic crystal ring resonator is designed and fabricated. Six sharp resonant peaks dominate the photoluminescence (PL) spectrum ranging from 1500 to 1600 nm at room temperature. The light emission enhancement is due to Purcell effect and high collection efficiency of the PCRR verified by calculated far-field patterns. The Purcell factor of the PCRR is estimated from enhancement factor and increased collection efficiency. The linewidth of the emission of a single Ge quantum dot is estimated from the Purcell factor.