TheRPSmethod,whichintegratestherealnumericalsolution,theperturbationsolutionandtheshootingsolutionreasonably,canobtainthecomplexsolutionofaslabwaveguidewithsmallgain/lossregionswithoutsearchingtherootintheentirecomplexplan.ArevisiontotheRPSmethodispresentedsothatitcandealwiththewaveguideincludinglargegain/lossregions.Theapplicationindicatedthatthesimulationresultsareprecise.
