Shubeita, G. T.Sekatskii, S. K.Riedo, B.Dietler, G.Durig, U.2007-06-202007-06-202007-06-20200010.1063/1.1287234https://infoscience.epfl.ch/handle/20.500.14299/9052Scanning near-field optical microscopy based on the heterodyne phase-controlled oscillator methodtext::journal::journal article::research article