Toward the Extension of High Order Harmonic Spectroscopy to Complex Molecules: Investigation of Aligned Hydrocarbons
High-order harmonic generation is as a powerful tool for the study of molecular properties. Up to now this investigation tool has been confined to simple molecules, with a relatively high ionization potential, since ionization saturation hindered its exploitation to fragile molecules. In this work we show that such limitation can be overcome by using mid-IR ultrashort driving pulses; as prototypical molecules we considered hydrocarbons. Clear signatures of the highest occupied molecular orbital were found in the harmonic spectra generated in unsaturated aligned hydrocarbons like acetylene, ethylene, allene and 1,3-butadiene. Our findings demonstrate that high-order harmonic generation spectroscopy can be extended to complex molecular species.
KeywordsHarmonic Spectrum Attosecond Pulse Ionization Saturation High Ionization Potential Saturation Issue
We acknowledge the financial support from the ECs Seventh Framework Programme (LASERLAB-EUROPE, Grant Agreement No. 228334), EPSRC Grant No. EP/E028063/1, and the partial support from Fondazione Cariplo (Project No. 2009–2562).
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