Whenadielectricmeta-atomisplacedintoasubwavelengthmetallicaperture,20-foldenhancedelectromagnetictransmissionthroughtheapertureisrealizedatthemeta-atom’sresonantfrequency.Additionally,whentheincidentelectromagneticpowerincreases,thermalenergygatheredbythemeta-atom,whichisconvertedfromelectromagneticlosses,cancausethemeta-atom’stemperaturetoincrease.Becauseofthehightemperaturecoefficientofthemeta-atom’sresonantfrequency,thistemperatureincreasecausesablueshiftinthetransmissionpeak.Therefore,thisfrequency-dependentenhancedelectromagnetictransmissionevenproducesanonlineareffectatlowincidentpowers.Overanincidentpowerrangefrom0to20dBm,measuredandsimulatedspectranearthemeta-atom’sresonantfrequencyshowdistinctlynonlineartransmission.
