Fabrication and optical properties of thin films with sol-gel derived di-ureasils doped with Disperse Red 1

We report the fabrication and the structural and optical characterization of transparent spin coated films (average thickness values of 4.9 +/- 0.1 mu m) of organic-inorganic hybrids (di-ureasils) doped with the Disperse Red 1 (DR1) chromophore. The refractive index was measured by prism coupling and spectroscopic ellipsometry revealing that the inclusion of DR1 induces a refractive index increase of similar to 1.0 x 10(-2) at 1550 nm, with respect to the non-doped host. Under UV exposure, the refractive index values of the DR1-doped hybrids decreased (-5 x 10(-3), at 1550 nm) due to a conformational alteration of DR1, as suggested by infrared and Raman spectroscopies. The global results indicate that DR1 doped di-ureasils are promising candidates as self-patternable planar waveguides for nonlinear integrated optics and photonic applications.