TRANSVERSE-MODE BEHAVIOR IN NATIVE-OXIDE-DEFINED LOW-THRESHOLD VERTICAL-CAVITY LASERS

Data are presented characterizing the transverse mode behavior of AlAs /GaAs/InGaAs vertical-cavity surface-emitting lasers fabricated using a native-oxide process. The native-oxide process results in laser diod es with active regions defined to be 10, 8, and 4 mu m squares. We sho w that the transverse lasing mode is influenced by mirror reflectivity , with significant mode changes occurring with drive current for 8-10 mu m devices in the ranges of one to four times threshold. In smaller devices of 4 mu m square dimension, the transverse mode at threshold a ppears as a lowest order mode.