An electrically induced probe of the modes of a plasmonic multilayer stack

Shuiyan Cao (1, 2) , Moustafa Achlan (1) , Jean-François Bryche (3, 4) , Philippe Gogol (3) , Gérald Dujardin (1) , Georges Raşeev (1) , Eric Le Moal (1) , Elizabeth Boer-Duchemin (1)

1 Nanophysique et Surfaces
2 Department of Applied Physics, Nanjing University of Aeronautics and Astronautics
3 C2N (UMR_9001) - Centre de Nanosciences et Nanotechnologies
4 LN2 - Laboratoire Nanotechnologies Nanosystèmes

A new single-image acquisition technique for the determination of the dispersion relation of the propagating modes of a plasmonic multilayer stack is introduced. This technique is based on an electrically-driven, spectrally broad excitation source which is nanoscale in size: the inelastic electron tunnel current between the tip of a scanning tunneling microscope (STM) and the sample. The resulting light from the excited modes of the system is collected in transmission using a microscope objective. The energy-momentum dispersion relation of the excited optical modes is then determined from the angle-resolved optical spectrum of the collected light. Experimental and theoretical results are obtained for metal-insulator-metal (MIM) stacks consisting of a silicon oxide layer (70, 190 or 310 nm thick) between two gold films (each with a thickness of 30 nm). The broadband characterization of hybrid plasmonic-photonic transverse magnetic (TM) modes involved in an avoided crossing is demonstrated and the advantages of this new technique over optical reflectivity measurements are evaluated.

Domaines: Optique [physics.optics]; Science des matériaux [cond-mat.mtrl-sci]; Optique / photonique

Shuiyan Cao, Moustafa Achlan, Jean-François Bryche, Philippe Gogol, Gérald Dujardin, et al.. An electrically induced probe of the modes of a plasmonic multilayer stack. Optics Express, 2019, 27 (23), pp.33011. ⟨10.1364/OE.27.033011⟩. ⟨hal-02340575⟩