Programme

P.30 -- Poster, VCTP-45

Date: Tuesday, 13 October 2020

Time: 08:30 - 10:00

Tomography of partially aligned molecules

Cong-Minh Tran, Khang Tran, Cam-Tu Le, Ngoc-Loan Phan

Ho Chi Minh City University of Education, Ho Chi Minh City, Vietnam

High-order harmonic generation (HHG), emitted from atoms and molecules exposed to an ultrashort intense laser pulse, is rich in structured information. One of the applications of HHG is to reconstruct the highest-occupied molecule orbital (HOMO) of molecules. In many theoretical studies on tomography, the authors have assumed that the molecules are perfectly aligned before interacting with the probe laser [1], [2]. However, with the recent alignment techniques [3], [4] the perfect alignment is impossible to archive [5]. Therefore, considering and clarifying the effect of the partial alignment of molecular samples into the tomography procedure is necessary. To our best of knowledge, this issue is rarely reported. In this report, we study the influence of molecular alignment on the quality of the reconstructed molecular HOMO using HHG form simple molecules N2 and O2. The HHGs are calculated by the semi-classical Lewenstein three-step model [6]. The alignment quality is varied in two ways: (i) using an approximated analytical formula, and (ii) adopting a numerical solution of solving the time-dependent Schrodinger equation for rotating molecules in the alignment laser field. Results show that the molecular HOMO of a molecular sample with a low degree of alignment is less structural due to the averaged effect. REFERENCES [1] J. Itatani, J. Lavesque, D. Zeidler, H. Niikura, H. Pépin, J. C. Kieffer, P. B. Corkum, and D.M. Villeneuve, Nature 432, 867 (2004). [2] J. C. Kieffer, P. B. Corkum, and D. M. Villeneuve, 432, 1 (2004). [3] M. Qin and X. Zhu, Opt. Laser Technol. 87, 79 (2017). [4] V. H. Le, A. T. Le, R. H. Xie, and C. D. Lin, Phys. Rev. A - At. Mol. Opt. Phys. 76, 1 (2007). [5] M. Lein, R. De Nalda, E. Heesel, N. Hay, E. Springate, R. Velotta, M. Castillejo, P. L. Knight, and J. P. Marangos, J. Mod. Opt. 52, 465 (2005). [6] M. Lewenstein, P. Balcou, M. Y. Ivanov, and A. L. Huillier, 49, 16 (1994).

Presenter: Tran Cong Minh

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