FOLDED-CAVITY SURFACE-EMITTING INGAAS-GAAS LASERS WITH LOW-THRESHOLD CURRENT-DENSITY AND HIGH-EFFICIENCY

Folded-cavity surface-emitting InGaAs-GaAs lasers (FCSEL's) that emplo y high-quality internal 45 degrees deflectors are demonstrated with lo w-threshold current density and high efficiency. A simplified process involving a stop etch to position the surface emitting output mirror c lose to the waveguide and ion-beam-etching GIBE) to form the 45 degree s deflecting mirror is presented, FCSEL's (cavity length 800 mu m) wit h two 45 degrees deflectors, are obtained with threshold current densi ty as low as 112.5 A/cm(2) and surface-emission external quantum effci ency as high as 65% (0.82 W/A). The additional loss contributed by the folded-cavity design is estimated as 4.2 cm(-1).