Using the all-optical poling method, we observed the formation of a surface-relief grating (SRG) in an amorphous polymer film containing azo dye molecules in side chain positions. The experiment consists of a seeding-type process. We used a recently described experimental setup that permits a periodic nonlinear pattern to be produced by the index dispersion of glass. The particular configuration permits photoinduced translation diffusion of the azo chromophores to be observed as the origin of the SRG formation. Analyses of the gratings recorded by use of s (TE) and p (TM) polarization of the writing beams are conducted by atomic-force microscopy. The effect is attributed to mass transport from regions of high isomerization activity to regions of lower activity.
© 2004 Optical Society of America
(160.5470) Materials : Polymers
(190.0190) Nonlinear optics : Nonlinear optics
(190.2620) Nonlinear optics : Harmonic generation and mixing
(260.0260) Physical optics : Physical optics
(350.3390) Other areas of optics : Laser materials processing
Aleksandra Apostoluk, Jean-Michel Nunzi, and Céline Fiorini-Debuisschert, "Photoinduction of surface-relief gratings during all-optical poling of polymer films," Opt. Lett. 29, 98-100 (2004)