Imperial College London
Dr Zair

Dr Zair

Faculty of Natural Sciences, Department of Physics

Academic Visitor
 
 
 
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Contact

 

+44 (0)20 7594 7720a.zair

 
 
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Location

 

6M75Blackett LaboratorySouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@inproceedings{Perez-Hernandez:2009:13/134004,
author = {Perez-Hernandez, JAPH and Hoffmann, DJH and Zair, AZ and Chipperfield, LEC and Plaja, LP and Ruiz, CR and Marangos, JPM and Roso, LR},
doi = {13/134004},
pages = {1--9},
title = {Extension of the cut-off in high-harmonic generation using two delayed pulses of the same colour},
url = {http://dx.doi.org/10.1088/0953-4075/42/13/134004},
year = {2009}
}
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RIS format (EndNote, RefMan)

TY  - CPAPER
AB  - We demonstrate a novel technique for an extension of the cut-off frequency in high-harmonic generation using a shaped field, consisting of two delayed pulses, identical in all parameters except a carrier envelope phase shift of pi. We obtain high harmonics up to an energy of 5.5U(p) + I(p), surpassing the conventional limit of 3.17U(p) + I(p). For high intensities approaching the threshold for barrier suppression ionization, beyond which no harmonics are generated, this mechanism acquires practical importance as a means to overcome the limit imposed by saturation. We analyse the underlying mechanism using both classical and quantum approaches, and highlight the role of the shaped field in modifying the electron trajectories in the continuum to enhance the collection of kinetic energy from the driving field. Of greatest importance are the trajectories describing electrons ionized across the first peak of the laser field which receive the enhanced kinetic energies responsible for the cut-off extension above the conventional limit. Interestingly, the most energetic trajectories do not contribute to the harmonic cut-off in the single pulse case. We conclude with a discussion of the sub-cycle structure of the emitted harmonic radiation and possible applications of the technique.
AU  - Perez-Hernandez,JAPH
AU  - Hoffmann,DJH
AU  - Zair,AZ
AU  - Chipperfield,LEC
AU  - Plaja,LP
AU  - Ruiz,CR
AU  - Marangos,JPM
AU  - Roso,LR
DO  - 13/134004
EP  - 9
PY  - 2009///
SN  - 0953-4075
SP  - 1
TI  - Extension of the cut-off in high-harmonic generation using two delayed pulses of the same colour
UR  - http://dx.doi.org/10.1088/0953-4075/42/13/134004
UR  - http://iopscience.iop.org/0953-4075/42/13/134004/pdf/0953-4075_42_13_134004.pdf
UR  - http://iop/
ER  -
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