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Ultrafast transient optical loss dynamics in exciton-plasmon nano-assemblies

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Details

Original languageEnglish
Pages (from-to)6558-6566
Number of pages9
JournalNanoscale
Volume9
Issue number19
DOIs
Publication statusPublished - 11 Apr 2017
Externally publishedYes
Publication typeA1 Journal article-refereed

Abstract

We study the exciton-plasmon dynamics that lead to optical loss mitigation via ultrafast transient absorption spectroscopy (UTAS) on hybrid aggregates of core-shell quantum dots (QDs) and Au nanoparticles (NPs). We highlight that generating hot electrons in plasmonic NPs contributes to the transient differential absorption spectrum under optical excitation. The results suggest modifying the method of analyzing the transient absorption spectra of loss mitigated systems. Additionally, we investigate the effect of Electron Oscillation frequency-Phonon Resonance Detuning (EOPRD) on loss mitigation efficiency. Moreover, power dependent UTAS reveal a frequency pulling like effect in the transient bleach maximum towards the gain emission. We show that the appropriate choice of the pump wavelength and by changing the pump power we can conclusively prove the existence of loss mitigation using UTAS. Finally, we study the transient kinetics of hybrid gain-plasmon systems and report interesting hybrid transient kinetics.

Keywords

  • COUPLED METAL NANOPARTICLES, ELECTRONIC RELAXATION, METAMATERIALS, GAIN, GOLD, NANOCRYSTALS, FEMTOSECOND, PARTICLES, ARRAYS