Electro-optic effect of dye-doped silica thin films

Abstract

Sol-gel-processed silica films doped with Disperse red 1 (DR1) as well as sol-gel-processed DR1/TiO 2 /SiO 2 films are prepared. The reaction process of sol-gel system is discussed theoretically. The optimal preparation for the dye-doped silica film is investigated as well. The content of catalyzer and the various mol ratio of raw materials in starting solution have influence on the electro-optic performance of the hybrid films. The film was spin-coated on the ITO coated glass substrate and rapidly condensed by evaporation of the solvent. Disperse red 1 (DR1) are doped in the three-dimensional silicon dioxide/titanium dioxide network possessing a high electro-optic coefficient r 33 . The EO coefficients of the poled DR1/SiO 2 films and the poled DR1/TiO 2 /SiO 2 films achieved 65 pm/V and 72 pm/V, respectively. An EO measurement system is fabricated. The hybrid films are spin coated on the low reflection mirror and corona poled after aging in order to induce the nonlinear performance. The EO output signals of the two silica films are detected. The experimental resultsshow that the EO output signals change both amplitude and frequency with the input signal. The nonlinearity of the poled DR1/SiO 2 films is relaxed less than 5% after 2000 h at 80℃. The EO coefficient of DR1/TiO 2 /SiO 2 films is relaxed less than 5% after 2500 h at 80℃ The excellent thermal stability of the hybrid organic/inorganic film has potential applications in the fields of electro-optics and optoelectronics.