Field-free molecular alignment of asymmetric top molecules using elliptically polarized laser pulses

International audienceWe show theoretically that a short specific elliptically polarized laser pulse driving an asymmetric top molecule can induce postpulse revivals of three-dimensional (3-D) alignment. By choosing the field ellipticity resulting in the best compromise between the alignment of two molecular axes, we demonstrate that efficient 3-D alignment can be achieved at low temperature. In the experiment, the field-free alignment of moderately cool ethylene molecules is probed by using a technique based on the optical Kerr effect. Control of 3-D field-free alignment opens the door to a large range of applications in chemistry as well as in molecular optics