Fisher Information Dark States and plasmonic resonances

¹ Optics Research Cluster, Imaging Physics Department, Delft University of Technology, Van der Waalsweg 8, 2628 CH Delft, The Netherlands
² ASML Research Netherlands B.V., De Run 6501, 5504 DR, Veldhoven, The Netherlands

^* e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.
^** e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.
^*** e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.

Published online: 22 September 2025

Abstract

In this talk, we discuss the effect of plasmonic resonances on the Fisher information in the far field. We consider a metallic nanowire embedded in a silicon substrate, illuminated by a dark-field focused spot, and we investigate how its position can be estimated from the scattered far-field intensities. The Fisher information is computed for both lateral and longitudinal displacements of the nanowire, and the dependence on the illumination frequency is analyzed. We compute the complex resonance frequencies of the nanowires and show that frequencies near the real part of the plasmonic resonance frequency enhance the Fisher information. However, at the resonance frequency itself, the Fisher information drops sharply, leading to an Information Dark State in which the position of the nanowire becomes nearly undetectable. This effect is analyzed and illustrated for both gold and silver nanowires.