Defects management in the gain media of GeSn micro-disk lasers

We fabricated a Ge 0.92 Sn 0.08 micro-disk laser with a lasing threshold as low as 20-30 kW/cm2 at 75 K. A specific etching process was developed to remove the dense array of misfit dislocations from the gain medium. Further surface treatments and passivations improved the lasing dynamics.