Optimization of field-free molecular alignment by phase-shaped laser pulses

E. Hertz (1, 2) , A. Rouzee (1, 2) , S. Guerin (1, 2) , B. Lavorel (1, 2) , O. Faucher (1, 2)

1 LPUB - Laboratoire de Physique de l'Université de Bourgogne
2 ICB - Laboratoire Interdisciplinaire Carnot de Bourgogne

We theoretically demonstrate the optimization of field-free molecular alignment by phase-shaped femtosecond laser pulses. The effect is assessed in O2 at T = 60 K under realistic conditions of intensity and pulse shaping. The spectral laser phase is sampled through 128 control parameters and a self learning evolutionary algorithm combined with a nonperturbative regime calculation is used in order to design the specific phase that maximizes the degree of alignment. The postpulse molecular alignment appears significantly enhanced compared to a Fourier-transform-limited pulse of same energy. The analysis of the target state reveals that the solution is close to the optimal one.

Domaines: Optique [physics.optics]

E. Hertz, A. Rouzee, S. Guerin, B. Lavorel, O. Faucher. Optimization of field-free molecular alignment by phase-shaped laser pulses. Physical Review A : Atomic, molecular, and optical physics [1990-2015], 2007, 75, pp.031403. ⟨10.1103/PhysRevA.75.031403⟩. ⟨hal-00397082⟩