Optically pumped rolled-up InAs/InGaAsP quantum dash lasers at room temperature

We have investigated the fabrication and optical performance of free-standing rolled-up InGaAsP tube optical cavities, wherein self-organized InAs quantum dots or dashes are incorporated as the gain media. Such tubular optical cavities are formed when the coherently strained InAs/InGaAsP quantum dot/dash nanomembrane is selectively released from the host substrate. We have achieved lasing from rolled-up InAs/InGaAsP quantum dash microtubes at room temperature under continuous wave optical pumping. The measured threshold is ∼6 µW, and the Purcell factor and the spontaneous emission coupling factor are estimated to be ∼6.54 and ∼0.87, respectively. (invited paper)