Electrical poling induces polar ordering of molecules in a grating that has been holographically inscribed on a thin film of polymer with azobenzene side chains. The resulting χ(2) grating, seen by second-harmonic-generation (SHG) near-field scanning optical microscopy, can have a periodic structure that is significantly different from the topographical image. The far-field linear and SHG diffraction patterns correlate well with the grating structures. Poling of the thin-film grating, which presumably has photodriven nonuniform material properties within each period, leads to the more complex structure of the χ(2) grating.
© 2003 Optical Society of America
(180.5810) Microscopy : Scanning microscopy
(190.4400) Nonlinear optics : Nonlinear optics, materials
(230.1950) Optical devices : Diffraction gratings
(230.4320) Optical devices : Nonlinear optical devices
(240.4350) Optics at surfaces : Nonlinear optics at surfaces
R. D. Schaller, R. J. Saykally, Y. R. Shen, and F. Lagugné-Labarthet, "Poled polymer thin-film gratings studied with far-field optical diffraction and second-harmonic near-field microscopy," Opt. Lett. 28, 1296-1298 (2003)