All-optical manipulation of azo-dye molecules

A challenging issue in the field of the design of devices for photonic applications is to achieve complete manipulation of the molecular order. Azo-dye aromatic polymers have been shown to offer interesting prospects for material engineering using light matter interactions. Dual-frequency irradiation using appropriate combinations of circular beams polarizations are demonstrated to enable full control of the molecular polar rotation. More recent results on photoinduced surface-relief gratings have also opened the way of molecular translation control using optical fields. Understanding of the relevant parameters of molecular translation processes is a key issue for optimization of such an optomechanical effect: a simple model accounting qualitatively for the essential features of photoinduced surface-relief gratings will be presented.