Nonlinear plasmonic response of doped nanowires observed by infrared nanospectroscopy. (31st December 2018)

• Record Type: Journal Article
• Authors: Lang, Denny; Balaghi, Leila; Winnerl, Stephan; Schneider, Harald; Hübner, René; Kehr, Susanne C; Eng, Lukas M; Helm, Manfred; Dimakis, Emmanouil; Pashkin, Alexej
• Is Part Of: Nanotechnology. Volume 30:Number 8(2019)
• Publication Date: 2018-12-31
• Subjects: s-SNIM -- infrared nanospectroscopy -- nanowires -- free-electron laser -- nonlinear plasmonics -- InGaAs; Nanotechnology -- Periodicals; Nanotechnology -- Periodicals; Nanotechnology; Publications périodiques; Nanotechnologies; Periodicals; 620.5
• DOI: 10.1088/1361-6528/aaf5a7
• Languages: English
• ISSNs: 0957-4484

Abstract

Abstract: We report a strong shift of the plasma resonance in highly-doped GaAs/InGaAs core/shell nanowires (NWs) for intense infrared excitation observed by scattering-type scanning near-field infrared microscopy. The studied NWs show a sharp plasma resonance at a photon energy of about 125 meV in the case of continuous wave excitation by a CO2 laser. Probing the same NWs with the pulsed free-electron laser with peak electric field strengths up to several 10 kV cm −1 reveals a power-dependent redshift to about 95 meV and broadening of the plasmonic resonance. We assign this effect to a substantial heating of the electrons in the conduction band and subsequent increase of the effective mass in the nonparabolic Γ-valley.