Nesci, A.Dändliker, R.Herzig, H. P.2009-04-222009-04-222009-04-22200110.1364/OL.26.000208https://infoscience.epfl.ch/handle/20.500.14299/37833Quantitative amplitude and phase measurement by use of a heterodyne scanning near-field optical microscopetext::journal::journal article::research article