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Plasmonic generation of attosecond pulses and attosecond imaging of surface plasmons
| Content Provider | Semantic Scholar |
|---|---|
| Author | Lupetti, Mattia |
| Copyright Year | 2015 |
| Abstract | Attosecond pulses are ultrashort radiation bursts produced via high harmonic generation (HHG) during a highly nonlinear excitation process driven by a near infrared (NIR) laser pulse. Attosecond pulses can be used to probe the electron dynamics in ultrafast processes via the attosecond streaking technique, with a resolution on the attosecond time scale. In this thesis it is shown that both the generation of attosecond (AS) pulses and the probing of ultrafast processes by means of AS pulses, can be extended to cases in which the respective driving and streaking fields are produced by surface plasmons excited on nanostructures at NIR wavelengths. Surface plasmons are optical modes generated by collective oscillations of the surface electrons in resonance with an external source. In the first part of this thesis, the idea of high harmonic generation (HHG) in the enhanced field of a surface plasmon is analyzed in detail by means of numerical simulations. A NIR pulse is coupled into a surface plasmon propagating in a hollow core tapered waveguide filled with noble gas. The plasmon field intensity increases for decreasing waveguide radius, such that at the apex the field enhancement is sufficient for producing high harmonic radiation. It is shown that with this setup it is possible to generate isolated AS pulses with outstanding spatial and temporal structure, but with an intensity of orders of magnitude smaller than in standard gas harmonic arrangements. In the second part, an experimental technique for the imaging of surface plasmonic excitations on nanostructured surfaces is proposed, where AS pulses are used to probe the surface field by means of photoionization. The concept constitutes an extension of the attosecond streak camera to ``Attosecond Photoscopy'', which allows space- and time-resolved imaging of the plasmon dynamics during the excitation process. It is numerically demonstrated that the relevant parameters of the plasmonic resonance buildup phase can be determined with subfemtosecond precision. Finally, the method used for the numerical solution of the Maxwell's equations is discussed, with particular attention to the problem of absorbing boundary conditions. New insights into the mathematical formulation of the absorbing boundary conditions for Maxwell's equations are provided. |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | http://www2.mpq.mpg.de/APS/data/dissertationen/LupettiMattia.pdf |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
