Hybridoctagonal-ringmicrolasersareinvestigatedforrealizingastableoutputfromasiliconwaveguidebasedonatwo-dimensionalsimulation.Theinnerradiusoftheringisoptimizedtoachievesingle-modeandlow-thresholdoperation.Usingthepinylsiloxane-benzocyclobutene(DVS-BCB)bondingtechnique,ahybridAlGaInAs/Sioctagonal-ringmicrolaserverticallycoupledtoasiliconwaveguideisfabricatedwithasidelengthof21.6μmandaninnerradiusof15μm.Asingletransverse-modeoperationisachievedwithathresholdcurrentdensityof0.8kA∕cm~2andaside-modesuppressionratioabove30dB,andastableoutputfromthelowersiliconwaveguideisobtained.