Abstract:We report the fabrication and the optical characterization of a hybrid tunable integrated optical filter. It consists of a diffused ionexchanged channel waveguide on a borosilicate glass substrate with a cover of the same glass to form a gap filled with a holographic grating. The grating morphology, called POLICRYPS (POlymer LIquid CRYstal Polymer Slices), is made of alternating stripes of polymer and liquid crystal acting as overlayer for the underneath waveguide. The filter structure includes aluminum coplanar electrodes to electrically control the grating properties, allowing the tunability of the filter. The electric driving power required to tune the filter obtained was in the range of submilliwatts due to the efficient liquid crystal electro-optic effect. A. d'Alessandro, R. Asquini, C. Gizzi, R. Caputo, A. Veltri, C. Umeton, and A. V. Sukhov, "Electro-optic properties of switchable gratings made of polymer and nematic liquid crystal slices," Opt. Lett. 29, 1405-1407 (2004 1005-1019 (1996). 14. T. A. Birks, P. St. J. Russell, and D. O. Culverhouse, "The acousto-optic effect in single-mode fiber tapers and couplers," J. Lightwave Technol. 14, 2519-2529 (1996). 15. J. Zou, F. Zhao, and R. T. Chen, "Two-step K+-Na+ and Ag+-Na+ ion-exchanged glass waveguides for Cband applications," Appl. Opt. 41, 7620-7626 (2002). 16. L. De Sio, R. Caputo, A. De Luca, A. Veltri, C. Umeton, and A. V. Sukhov, "In situ optical control and stabilization of the curing process of holographic gratings with a nematic film-polymer-slice sequence structure," Appl.
