Controlled excitation of quantum emitters by nonlinear plasmonic nearfields
Final Report Abstract
In this project, we investigated the nonlinear emission of plasmonic nanorods. Its main components are the coherent second and third harmonics of the fundamental laser pulse and the incoherent photoluminescence of the hot electron gas excited in a multiphoton process. We investigated how these three contributions vary when the electron gas and lattice temperatures are changed by a blue heating laser pulse and found that the nonlinear photoluminescence is rather sensitive to changes in the electron gas temperature, while the third harmonic is only affected by the lattice temperature. In a second branch, we compared the spatial emission patterns of these three nonlinear components. From previous work, we expected a switching of the third-harmonic emission pattern when the fundamental laser frequency is tuned through the third-order plasmon resonance of the nanorod. We have now confirmed this switching for the nonlinear photoluminescence by real-space imaging. Since the underlying source is always the same fundamental near-field, both switching patterns are consistent within the experimental noise. In the future, we plan to use these nonlinear near-fields to excite quantum emitters such as dye molecules or proteins at well controllable positions.
Publications
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Ultrafast Nonlinear Spectroscopy of Nanostructures, Dissertation, Bayreuth
Julian Obermeier
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Switching nonlinear emission patterns of plasmonic nanostructures, DPG SKM conference 2023, Dresden, Poster O 43.2
Valentin Dichtl, Kilian Wittman, Thorsten Schumacher & Markus Lippitz
