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MO: Fachverband Molekülphysik
MO 3: Diffraction and Coherences (with A)
MO 3.6: Talk
Monday, March 6, 2017, 18:30–18:45, N 6
Optimisation of strong laser field-free alignment using tailored light fields — •Evangelos Thomas Karamatskos1,2, Sebastian Raabe4, Andrea Trabattoni1, Terry Mullins1, Sebastian Trippel1,2, Arnaud Rouzee4, and Jochen Küpper1,2,3 — 1DESY, Hamburg, Germany — 2Universität Hamburg, Germany — 3CUI, Hamburg, Germany — 4Max-Born Institute, Berlin, Germany
Alignment of molecules with respect to the laboratory fixed frame [1] enables the realization of a large variety of experiments such as the determination of molecular frame photoangular distribution (MFPAD's) [2] or laser induced electron diffraction (LIED) where typically a strong degree of alignment is needed [3]. We present a combined theoretical and experimental effort to optimise the degree of laser field-free alignment of molecules in the gas phase. We start by solving the time-dependent rotational Schrödinger equation coupled to a non-resonant laser field and a static electric field and use an iterative learning-loop algorithm to determine the ideal pulse shape that optimises the degree of alignment. These calculations serve as a guide to complement the experiments where the alignment laser pulse form is optimally tailored. We discuss the simulation results and the experimental realization of two-pulse impulsive alignment on the example of the linear molecule carbonyl sulfide (OCS) and give an outlook for the use of pulse shaping techniques to achieve strongly aligned asymmetric top molecules. [1] Stapelfeldt et al., Rev. Mod. Phys. 75, 543 (2003) [2] Hansen et al. Phys. Rev. Lett. 106, 073001 (2011) [3] Pullen et al., Nature Communications 6, 7262 (2015)