The effects of tightly focused, higher-order laser beams on the photoinduced molecular migration and surface deformations in azobenzene polymer films are investigated. We demonstrate that the surface relief is principally triggered by longitudinal fields, i.e., electric fields polarized along the optical axis of the focused beam. Our findings can be explained by the translational diffusion of isomerized chromophores when the constraining effect of the polymer–air interface is considered.
© 2006 Optical Society of America
Optics at Surfaces
Original Manuscript: September 15, 2005
Manuscript Accepted: October 14, 2005
Yann Gilbert, Renaud Bachelot, Pascal Royer, Alexandre Bouhelier, Gary P. Wiederrecht, and Lukas Novotny, "Longitudinal anisotropy of the photoinduced molecular migration in azobenzene polymer films," Opt. Lett. 31, 613-615 (2006)