A hybrid film where organic chromophores are attached to silica networks was fabricated by sol-gel process. The electro-optic coefficient r(33) was measured to be 16pm/V and the poled film retained 95% of its initial r(33) value after 800 hours at room temperature. A Mach-Zehnder modulator was fabricated, which supported the two lowest excited modes, TM(00) and TM(10).