|
|
| Identifier |
000363276 |
| Title |
Attosecond Metrology and Application of High Harmonics |
| Alternative Title |
Μετρολογία παλμών χρονοδιάρκειας αττοδευτερολέπτων και εφαρμογές υψηλής τάξης αρμονικών |
|
Author
|
Kruse, Jann Eike
|
|
Thesis advisor
|
Χαραλαμπίδης, Δημήτρης
Τζάλλας, Πάρης
|
| Abstract |
Real-time studies of ultra-fast evolving quantum systems require even
faster probe mechanisms. For electronic systems on the atomic scale sub-femtosecond laser pulses are suitable. High-order harmonic generation can
produce the necessary broad spectrum to support such short pulses. Under
certain phase-matching conditions a subset of the emitted radiation can be
well phase-locked resulting in attosecond laser pulses. To extract sound information from the experiments' results, accurate and reliable temporal and
structural assessment of these pulses is indispensable. Various attosecond
metrology methods have been proposed and some applied. Most of these
rely either on a two-color photo-ionization of an atomic system by both the
extreme-ultraviolet attosecond pulses and the fundamental infrared radiation
together or they rely on a second-order autocorrelation based on a two-photon ionization by the mere attosecond pulses alone.
Two techniques underlying most of the attosecond metrology methods
were compared and evaluated. These are the reconstruction of attosecond
beating by interference of two-photon transitions (RABITT) and the second-
order intensity volume-autocorrelation (2IVAC). Despite considerable controversy on the applicability and reliability of these two methods, a direct comparison between them has been missing. This thesis _lls that gap and examines the strengths and limitations of these and other metrology methods
based on them. In this context a dispersionless second-order autocorrelator
was set up and tested by measuring the interferometric autocorrelation of
the 1.87 PHz _fth harmonic pulse. Both metrology methods were applied
and compared leading to the conclusion, that RABITT may underestimate
the pulse duration. The participation of di_erent quantum-paths to the high
harmonic generation process in gases, shown here for several phase-matching conditions, has rami_cations on applying cross-correlation methods for attosecond metrology as well as on atomic-molecular tomography and precision measurements with extreme ultraviolet (XUV) frequency combs. Additionally, studying the photo-dissociation dynamics of ethylene and oxygen, utilizing the same apparatus as used for the metrology, revealed their decay times of a few femtoseconds.
|
| Language |
English |
| Subject |
High-harmonic generation |
|
Laser-matter interaction |
|
Molecular dynamics |
|
Non-linear optics |
|
Optical autocorrelation |
|
Quantum interference |
|
Short pulse |
| Issue date |
2011-01-10 |
| Collection
|
School/Department--School of Sciences and Engineering--Department of Physics--Doctoral theses
|
|
|
Type of Work--Doctoral theses
|
| Views |
617 |
Attosecond Metrology and Application of High Harmonics
