Threshold reduction in pierced microdisk lasers

GaAs microdisk lasers with holes pierced through the disk surface are inves tigated for their threshold characteristics. Disks are fabricated with eith er a single hole or two diametrically opposite holes at various distances f rom the disk outer edge. Even though the disk area is reduced by only 1%, w e find that the lasing threshold for a disk with one hole is reduced by up to 50% compared to a disk with no hole. We attribute this reduction to the perturbation of nonlasing modes, which decreases the amplification of spont aneous emission in these modes and makes more carriers available to contrib ute to lasing. (C) 1999 American Institute of Physics. [S0003-6951(99)00301 -0].