Leakage radiation microscopy of surface plasmon polaritons A. Drezet, A. Hohenau, D. Koller, A. Stepanov, H. Ditlbacher, B. Steinberger, F. R. Aussenegg, A. Leitner, and J. R. Krenn Institute of Physics, Karl-Franzens University Graz, Universit¨ atsplatz 5 A-8010 Graz, Austria (Dated: October 29, 2018) We review the principle and methodology of leakage radiation microscopy (LRM) applied to surface plasmon polaritons (SPPs). Therefore we first analyse in detail the electromagnetic theory of leaky SPP waves. We show that LRM is a versatile optical far-field method allowing direct quantitative imaging and analysis of SPP propagation on thin metal films. We illustrate the LRM potentiality by analyzing the propagation of SPP waves interacting with several two dimensional plasmonic devices realized and studied in the recent years. PACS numbers: 1 arXiv:1002.0725v1 [physics.optics] 3 Feb 2010 Abstract