Abstract-Terahertz pulse shaping through propagation in a gas of symmetric top molecules

K. Hamraoui, P. Babilotte, F. Billard, E. Hertz, O. Faucher, L. H. Coudert, D. Sugny, and B. 
Lavorel

https://journals.aps.org/pra/accepted/35076NdeR1b1dc1467c928231c6a30bb745e593d5

Symmetric-top molecules of methyl iodide are irradiated with a terahertz pulse generated by a two-color plasma and shaped by a short propagation in air. A free-induction decay is emitted by the excited molecular sample and then propagates in air before detection. The experimental data show that the input terahertz pulse undergoes strong reshaping through absorption and dispersion. This leads to narrow wave packets at revival times due to the excitation of high rotational energy levels. Typically a THz burst of duration \simeq 15-20 ps is produced periodically, with a central frequency of \simeq 1 THz and a width that can be as narrow as 60--80 GHz. Pulse shaping based on propagation can be useful for quantum control in molecules. We provide a theoretical description of this wave propagation based on the Maxwell-Bloch equation. The observed experimental signal is in good accordance with the numerical simulations.

Abstract-Field-free molecular orientation by terahertz laser pulses at high temperature

http://pra.aps.org/abstract/PRA/v85/i6/e063418

M. Lapert¹ and D. Sugny^2,*
1Institut für Quanteninformationsverarbeitung, Universität Ulm, D-89069 Ulm, Germany
²Laboratoire Interdisciplinaire Carnot de Bourgogne (ICB), UMR 5209 CNRS-Université de Bourgogne, 9 Avenue A. Savary, BP 47 870, F-21078 Dijon Cedex, France

Received 29 May 2012; published 29 June 2012

We investigate to which extend a terahertz laser pulse can be used to produce field-free molecular orientation at high temperature. We consider laser pulses that can be implemented with the state of the art technology and we show that the efficiency of the control scheme crucially depends on the parameters of the molecule. We analyze the temperature effects on molecular dynamics and we demonstrate that for some molecules a noticeable orientation can be achieved at high temperature.

©2012 American Physical Society

URL:

http://link.aps.org/doi/10.1103/PhysRevA.85.063418

DOI:

10.1103/PhysRevA.85.063418

PACS:

33.80.-b, 42.50.Hz, 05.45.-a, 02.30.Ik

Abstract-Field-free molecular orientation by terahertz laser pulses at high temperature

M. Lapert and D. Sugny

Accepted Tuesday Jun 19, 2012

We investigate to which extend a THz laser pulse can be used to produce field-free molecular orientation at high temperature. We consider laser pulses that can be implemented with the state of the art technology and we show that the efficiency of the control scheme crucially depends on the parameters of the molecule. We analyze the temperature effects on molecular dynamics and we demonstrate that, for some molecules, a noticeable orientation can be achieved at high temperature.