The sol-gel synthesis of organic-inorganic composite materials with push pull azobenzene molecules covalently bonded to the silica matrix is used for fabricating low cost optical channel waveguides for integrated optics applications and optical information storage. The refractive index change is obtained through the orientation of the nonlinear active molecules induced by a trans-cis-trans photoisomerization process. The index change and anisotropy are created by illuminating the thin film at a wavelength located inside the absorption band of the chromophores. At short irradiation times, the induced birefringence and dichroism are the consequence of the usual reorientation phenomenon due to the trans-cis-trans isomerization. At long pumping times, a photobleaching is observed corresponding to an irreversible transformation in the silica matrix. This property is used to write channel waveguides and gratings.

Date Published: 13 October 1994
PDF: 12 pages
Proc. SPIE 2288, Sol-Gel Optics III, (13 October 1994); doi: 10.1117/12.188962

Published in SPIE Proceedings Vol. 2288:
Sol-Gel Optics III
John D. Mackenzie, Editor(s)