Inthispaper,wereportanexperimentaldemonstrationofenablingtechnologyexploitingresonantpropertiesofplasmonicnanoparticles,fortherealizationofwavelength-sensitiveultra-minituarized(4μm×4μm)opticalmetadevices.Tothisend,theexampleofa1.3/1.6μmwavelengthdemultiplexerisconsidered.Itstechnologicalimplementationisbasedontheintegrationofgoldcut-wire-basedmetalinesonthetopofasilicon-on-insulatorwaveguide.TheplasmonicmetalinesmodifylocallytheeffectiveindexoftheSiwaveguideandthusallowfortheimplementationofwavelength-dependentopticalpathways.The1.3/1.6μmwavelengthseparationwithextinctionratiobetweentwodemultiplexers’channelsreachingupto20dBisexperimentallydemonstrated.Theconsideredapproach,whichcanbereadilyadaptedtodifferenttypesofmaterialplanarlightwavecircuitplatformsandnanoresonators,issuitedfortheimplementationofagenericfamilyofwavelength-sensitiveguided-waveopticalmetadevices.