Temporal coherence of high-order harmonics generated at solid surfaces

Autor: Zsuzsanna Major, M. Behmke, Stefan Karsch, J. Keyling, G. Pretzler, C. Stelzmann, D. Hemmers
Rok vydání: 2013
Předmět:
Zdroj: Applied Physics B. 116:121-127
ISSN: 1432-0649
0946-2171
DOI: 10.1007/s00340-013-5658-0
Popis: We present interferometric measurements of the temporal coherence of high-order harmonics generated by reflection of a titanium sapphire laser off a solid surface. It is found that the coherence length of the harmonic emission is significantly reduced compared with the bandwidth limited case. To identify the responsible mechanism, the acquired data were analyzed by means of particle-in-cell simulations, whose results show good agreement between the calculated spectra and the measured coherence times. We show that the observed broadening can be understood consistently by the occurrence of a Doppler shift induced by the moving plasma surface, which is dented by the radiation pressure of the laser pulse. In this case, this Doppler effect would also lead to positive chirp of the emitted radiation.
Databáze: OpenAIRE
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