Advanced dry etching of GaAs/AlGaAs multilayer wafer with InAs quantum dot for circular defect in photonic crystal laser

We previously proposed the circular defect in two-dimensional photonic crystal (CirD) laser based on a GaAs/AlGaAs multilayer wafer, which is fabricated by dry etching. This CirD uses InAs quantum dot (QD) layers as gain medium, but this inhibits vertical improved etching process introducing three QD and three-step for fabricating laser. As result, structures with good profiles could be excellent optical properties were obtained. observed lasing deep under photoexcitation measurement first time.