6533b858fe1ef96bd12b5b0b

RESEARCH PRODUCT

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

Arnaud RouzéeStéphane GuérinEdouard HertzBruno LavorelOlivier Faucher

subject

Physics[PHYS.PHYS.PHYS-OPTICS]Physics [physics]/Physics [physics]/Optics [physics.optics][ PHYS.PHYS.PHYS-OPTICS ] Physics [physics]/Physics [physics]/Optics [physics.optics]Degree (graph theory)business.industryPhase (waves)Order (ring theory)Laser01 natural sciencesPulse shapingAtomic and Molecular Physics and Opticslaw.invention010309 opticsOpticslaw0103 physical sciencesFemtosecondAtomic physics010306 general physicsbusinessIntensity (heat transfer)Energy (signal processing)

description

We theoretically demonstrate the optimization of field-free molecular alignment by phase-shaped femtosecond laser pulses. The effect is assessed in ${\mathrm{O}}_{2}$ at $T=60\phantom{\rule{0.3em}{0ex}}\mathrm{K}$ 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.

https://hal.archives-ouvertes.fr/hal-00397082