InAs–InP (1.55- $\mu$m Region) Quantum-Dot Microring Lasers

In this letter, we demonstrate electrically pumped continuous-wave lasing at room temperature in microring lasers, which employ a quantum-dot gain medium. Lasing occurs in the important 1.55- $\mu$m telecom wavelength range. The 2-$\mu$m-wide ring waveguides are made from InGaAsP–InP (100) material suitable for active–passive photonic integrated circuits. Lasing in rings down to 22 $\mu$m in diameter is found, with a threshold current of 12.5 mA.