Photothermal heterodyne imaging of individual non-fluorescent nano-objects

Authors :: Berciaud, Stephane
Cognet, Laurent
Blab, Gerhard
Lounis, Brahim
Publication Year :: 2004
Publisher :: arXiv, 2004.
Abstract: We introduce a new, highly sensitive, and simple heterodyne optical method for imaging individual non-fluorescent nano-objects. A two orders of magnitude improvement of the signal is achieved compared to previous methods. This allows for the unprecedented detection of individual small absorptive objects such as metallic clusters (of 67 atoms) or non-luminescent semiconductor nanocrystals. The measured signals are in agreement with a calculation based on the scattering field theory from a photothermal-induced modulated index of refraction profile around the nanoparticle.<br />Comment: Submitted 25Mar04 to PRL