We introduce a new experimental method to measure the local electromagnetic density of states (LDOS) by integrating the differential scattering cross section. The signal detected essentially reflects the intrinsic scattering response of the photonic structures and renders the partial LDOS dominated by evanescent modes. We give a theoretical understanding of the LDOS image formation and show a qualitative agreement between experimental images and theoretical maps. This approach can be practically applied to the direct measurement of an optical antenna’s scattering efficiency and can provide valuable information for designing optimum structures utilized in radiative decay engineering.
© 2008 Optical Society of America
Original Manuscript: November 26, 2007
Revised Manuscript: December 21, 2007
Manuscript Accepted: January 2, 2008
Published: February 5, 2008
Vol. 3, Iss. 3 Virtual Journal for Biomedical Optics
C. Huang, A. Bouhelier, G. Colas des Francs, G. Legay, J.-C. Weeber, and A. Dereux, "Far-field imaging of the electromagnetic local density of optical states," Opt. Lett. 33, 300-302 (2008)