Strong-field control of the dissociative ionization of N₂O with near-single-cycle pulses

Abstract

The dissociative ionization of N 2 O by near-single-cycle laser pulses is studied using phase-tagged ion-ion coincidence momentum imaging. Carrier-envelope phase (CEP) dependences are observed in the absolute ion yields and the emission direction of nearly all ionization and dissociation pathways of the triatomic molecule. We find that laser-field-driven electron recollision has a significant impact on the dissociative ionization dynamics and results in pronounced CEP modulations in the dication yields, which are observed in the product ion yields after dissociation. The results indicate that the directional emission of coincident + N and + NO ions in the denitrogenation of the dication can be explained by selective ionization of oriented molecules. The deoxygenation of the dication with the formation of coincident + N 2 + + O ions exhibits an additional shift in its CEP dependence, suggesting that this channel is further influenced by laser interaction with the dissociating dication. The experimental Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.results demonstrate how few-femtosecond dynamics can drive and steer molecular reactions taking place on (much) longer time scales.

Phase- and intensity-dependence of ultrafast dynamics in hydrocarbon molecules in few-cycle laser fields

“…Therefore, populating the relevant states for deprotonation may require a higher recollision energy than populating the electronic ground state. The requirement of higher recollision energy has been shown to lead to an increased asymmetry amplitude for molecular double ionization [45]. …”

Three-dimensional momentum imaging of dissociation in flight of metastable molecules

“…One of the striking signatures of dissociation in flight in the coincidence time-of-flight (CTOF) spectrum is a long, curved stripe that extends from the prompt breakup region and terminates at the intact metastable ion time of flight. This signature has been noted in CTOF spectra from a myriad of studies [35][36][37][38][39][40][41][42][43][44][45][46][47][48].…”

Focus on coherent control of complex quantum systems

“…In 'Cooling molecular vibrations with shaped laser pulses: optimal control theory exploiting the timescale separation between coherent excitation and spontaneous emission' [24], Reich and Koch show how shaping the optical pulses in the optical pumping can be used to implement an optimal control protocol to perform laser cooling of molecules even if the Franck-Condon effects are unfavorable. Kbel et al demonstrate in 'Strong-field control of the dissociative ionization of N 2 O with near-single-cycle pulses' [25] how very short pulses (few femtoseconds) can drive and steer molecular reactions taking place on longer time scales by considering the dissociation of N 2 O molecules and that the laser creates oriented samples of molecular ions which undergo dissociation.…”