Abstract
Striking a metallic nanostructure with a short and intense pulse of light excites a complex out-of-equilibrium distribution of electrons that rapidly interact and lose their mutual coherent motion. Due to the highly nonlinear dynamics, the photo-excited nanostructures can generate energetic photons beyond the spectrum of the incident beam, where the shortest pulse duration is traditionally expected to induce the greatest nonlinear emission. Here, these photo-induced extreme ultrafast dynamics are coherently controlled by spectrally shaping a sub-10 fs pulse within the timescale of coherent plasmon excitations. Contrary to the common perception, it is shown that stretching the pulse to match its internal phase with the plasmon-resonance increases the second-order nonlinear emission by >25%. The enhancement is observed only when shaping extreme-ultrashort pulses (<20 fs), thus signifying the coherent electronic nature as a crucial source of the effect. A detailed theoretical framework that reveals the optimal pulse shapes for enhanced nonlinear emission regarding the nanostructures’ plasmonic-resonances is provided. The demonstrated truly-coherent plasma control paves the way to engineer rapid out-of-equilibrium response in solids state systems and light-harvesting applications.
Original language | English |
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Article number | 2100467 |
Journal | Laser and Photonics Reviews |
Volume | 16 |
Issue number | 7 |
DOIs | |
State | Published - Jul 2022 |
Keywords
- coherent control
- coherent plasmonic ultrafast enhancement
- ultrafast nanostructured nonlinearities
- ultrafast plasmonic dynamics
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Atomic and Molecular Physics, and Optics
- Condensed Matter Physics