Photonic crystal surface emitting lasers (PCSELs) based on InAs quantum dots-in-a-well

Lasers based on self-assembled InAs quantum dot (QD) gain media have attracted considerable attention due to their low sensitivity to operating temperature and low threshold current densities. Here we demonstrate an InAs QD based photonic crystal surface emitting laser (QD-PCSEL), which features the advantages of a surface emitter while simplifying the fabrication process compared to a VCSEL or VECSEL. The PCSEL fabrication process includes epitaxial regrowth, which enables the photonic crystal (PC) to be buried in the laser’s waveguide. One of the challenges is the removal of the native oxide before the regrowth. This includes a thermal treatment that can alter the QD gain medium. Our study indicates that a dot-in-a-well (DWELL) design, where the QDs are embedded in a QW, is stable during the regrowth. The PCSEL is tested by optical pumping and we present measurements of both light-input light-output and optical spectrum.