Taperedfiberswithdiametersrangingfrom1to4μmarewidelyusedtoexcitethewhispering-gallery(WG)modesofmicrocavities.Typically,thetransmissionspectrumofaWGcavitycoupledtoawaveguidearoundaresonanceassumesaLorentziandipmorphologyduetoresonantabsorptionofthelightwithinthecavity.Inthispaper,wedemonstratethatthetransmissionspectraofaWGcavitycoupledwithanultrathinfiber(500–700nm)mayexhibitbothLorentziandipsandpeaks,dependingonthegapbetweenthefiberandthemicrocavity.Byconsideringthelargescatteringlossofoff-resonantlightfromthefiberwithinthecouplingregion,thisphenomenoncanbeattributedtopartiallyresonantlightbypassingthelossyscatteringregionviaWGmodes,allowingittobecoupledbothtoandfromthecavity,thenmanifestingasLorentzianpeakswithinthetransmissionspectra.Thisimpliesthesystemcouldbeimplementedwithinabandpassfilterframework.
