Gradual degradation in 850-nm vertical-cavity surface-emittinglasers

摘要

The aging process is studied in proton-implanted 850-nmnvertical-cavity surface-emitting lasers (VCSEL's). We find evidence forna novel failure mode, which does not involve the growth of defects ornreduction in radiative efficiency. In the proposed failure mode, pointndefects migrate and passivate the dopant atoms in the VCSEL mirrors,nincreasing mirror resistance in the device center. Thus, current isnforced toward the lower resistance parallel path along the device edges,nwhere it does not contribute to lasing. We refer to this as then“current-shunting failure mechanism”. Evidence has beennfound to support this process for both 850- and 680-nm proton-implantednVCSEL's