Optical self-inscription in waveguides and pattern formation in sol-gel derived nanophase organo-silica films

Photoresponsive nanocomposite organically modified silica (ORMOSIL) films were prepared by solution sol-gel processing of organically modified silicon alkoxide compounds. Waveguiding at 488 nm proceeds with simultaneous self-inscription and permanently inscribed waveguides can be revealed by wet etching. Under certain conditions, self-inscription becomes chaotic, and filamentation is observed. A counterpropagating beam set-up allows simple optical devices like crosses and y-junctions to be created. Soliton-like behavior is exhibited at low laser power where couterpropagating self-inscribed beams undergo mutual trapping. The ORMOSIL films exhibit interesting patterns which may be associated with the relief of stress in the films. These patterns can be controlled to some extent by depositing self-inscribed features in the glassy medium.