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RESEARCH PRODUCT
Momentum Distribution of Electrons Emitted from Resonantly Excited Individual Gold Nanorods.
Gerd SchönhenseBenjamin FoersterMathias SchmittHans-joachim ElmersCarsten SönnichsenKatja KrügerMartin Lehrsubject
Materials scienceMechanical EngineeringPhysics::OpticsBioengineering02 engineering and technologyGeneral ChemistryElectron021001 nanoscience & nanotechnologyCondensed Matter PhysicsLaser01 natural scienceslaw.inventionCondensed Matter::Materials SciencePhotoemission electron microscopylawExcited state0103 physical sciencesFemtosecondPolaritonGeneral Materials ScienceNanorodAtomic physics010306 general physics0210 nano-technologyPlasmondescription
Electron emission by femtosecond laser pulses from individual Au nanorods is studied with a time-of-flight momentum resolving photoemission electron microscope (ToF k-PEEM). The Au nanorods adhere to a transparent indium–tin oxide substrate, allowing for illumination from the rear side at normal incidence. Localized plasmon polaritons are resonantly excited at 800 nm with 100 fs long pulses. The momentum distribution of emitted electrons reveals two distinct emission mechanisms: a coherent multiphoton photoemission process from the optically heated electron gas leads to an isotropic emission distribution. In contrast, an additional emission process resulting from the optical field enhancement at both ends of the nanorod leads to a strongly directional emission parallel to the nanorod’s long axis. The relative intensity of both contributions can be controlled by the peak intensity of the incident light.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2017-10-21 | Nano letters |