6533b82bfe1ef96bd128d355

RESEARCH PRODUCT

Alignment of linear molecules by short duration laser pulses

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Alignment of linear molecules is efficiently induced by strong linearly polarized laser pulses. In the case of short pulses with respect to molecular rotation, periodic alignment appears in field-free conditions after the extinction of the field. This manuscript presents three techniques where the value of allows to quantify alignment without molecular dissociation nor additional alignment. They use a weak time-delayed probe pulse which experiences the optical properties of an aligned sample and shows modification of its characteristics. The first of them measures a depolarization due to the birefringence of the sample. The second one is based on the defocusing produced by the spatial distribution of aligned molecules, and thus, the gradient of the refractive index. The last technique is based on the creation of a transient grating at the crossing of two intenses laser pulses. This grating leads to the diffraction of a weak probe pulse.