Title :
Dynamical coupling of molecular rotation and Coulomb explosion
Author :
Weber, S.J. ; Oppermann, Martin ; Frasinski, L.J. ; Marangos, J.P.
Author_Institution :
Blackett Lab., Imperial Coll. London, London, UK
Abstract :
Summary form only given. The first observation of 1/8<;sup>th<;/sup> rotational revival in impulsively aligned CO<;sub>2<;/sub> molecules probed by Coulomb explosion is reported. Such a dynamic gives insight in the coupling arising between rotation wavepacket and strong field dynamic. Field free molecular rotational alignment is nowadays a routine technique to achieve structural and dynamical measurements in the molecular frame [1]. It is a unique tool to study electron recollision in strong field physics as in High Harmonic Generation (HHG) spectroscopy and recollision-induced double ionisation and fragmentation. A rotational wavepacket is launch by an ultrashort pulse leading to periodic alignment of the molecules, so called “revivals”. Various experimental techniques are able to give insight in the rotational dynamic of the wavepacket as for example the direct visualization of the molecular bond orientation using velocity map imaging [2]. While the temporal evolution of such alignment is well represented by the expectation value <;cos<;sup>2<;/sup> θ> (0 is the angle between molecular bond and electric field polarisation), the experimental measurement of rotational periodic alignment can lead to significantly distorted revivals, especially with the presence of higher order terms as <;cos<;sup>n<;/sup> 0>with n=4,6. This has been shown especially with HHG, where the coupling of rotational wavepacket and angular yield of HHG is modulated differently, depending the molecule structure [3,4].
Keywords :
bonds (chemical); carbon compounds; molecular configurations; molecule-photon collisions; optical harmonic generation; photodissociation; rotational states; CO2; CO2 molecules; Coulomb explosion; HHG angular yield; direct visualization; dynamical coupling; dynamical measurement; electric field polarisation; electron recollision; expectation value; field free molecular rotational alignment; fragmentation; high harmonic generation spectroscopy; higher order terms; molecular bond orientation; molecular frame; molecule periodic alignment; molecule structure; recollision-induced double ionisation; rotational periodic alignment; rotational revival; strong field dynamics; strong field physics; structural measurement; temporal evolution; ultrashort pulse; velocity map imaging; wavepacket rotational dynamics; Couplings; Delays; Explosions; Ionization; Laboratories; Probes; Rotation measurement;
Conference_Titel :
Lasers and Electro-Optics Europe (CLEO EUROPE/IQEC), 2013 Conference on and International Quantum Electronics Conference
Conference_Location :
Munich
Print_ISBN :
978-1-4799-0593-5
DOI :
10.1109/CLEOE-IQEC.2013.6801023