Temporal coherence of propagating surface plasmons

Wang Tao (1) , Geneviève Comtet (1) , Eric Le Moal (2) , Gérald Dujardin (1) , Aurelien Drezet (3) , Serge Huant (3) , Elizabeth Boer-Duchemin (2)

1 PPM - Laboratoire de Photophysique Moléculaire
2 ISMO - Institut des Sciences Moléculaires d'Orsay
3 NEEL - NOF - Nano-Optique et Forces

The temporal coherence of propagating surface plasmons is investigated using a local, broadband plasmon source consisting of a scanning tunneling microscope. A variant of Young’s experiment is performed using a sample consisting of a 200 μm-thick gold film perforated by two 1-μm diameter holes (separated by 4 or 6 μm). The resulting interference fringes are studied as a function of hole separation and source bandwidth. From these experiments we conclude that apart from plasmon decay in the metal, there is no further loss of plasmon coherence from propagation, scattering at holes or other dephasing processes. As a result, the plasmon coherence time may be estimated from its spectral bandwidth.

Domaines: Autre [cond-mat.other]

Wang Tao, Geneviève Comtet, Eric Le Moal, Gérald Dujardin, Aurelien Drezet, et al.. Temporal coherence of propagating surface plasmons. Optics Letters, 2014, 39 (23), pp.6679. ⟨10.1364/OL.39.006679⟩. ⟨hal-02049141⟩