Unique top-driven low-threshold lasers by impurity-induced disordering

Top-driven lasers have been fabricated by impurity-induced disordering (IID). Compared with conventional top-driven lasers, that is, transverse-junction-stripe (TJS) lasers, the top-driven IID (TID) lasers are unique in that the carriers in the active quantum-well stripe, are injected vertically from (instead of laterally between) the cladding layers of the lasers. Because vertical injection is much more efficient than lateral injection, the threshold current of the TID lasers is lower than that of TJS lasers by a factor of 2-10. The lowest threshold current observed for the TID lasers was 1.6 mA under room-temperature continuous-wave (CW) operation. By using proper material design and device processing, the top n-type contact of the TID lasers obtained is virtually as good as the bottom n-type contact of conventional IID lasers. >