采用溶胶－凝胶法制备了SiO₂－TiO₂平板光波导，计算了平板光波导通光条件，分析了硅／钛溶胶－凝胶材料的热性能，观测了平板光波导的结构形貌，并测试了其通光损耗。结果表明：经过200C，30 min干燥处理的凝胶薄膜呈疏松多孔状态，对于非对称平板波导，存在芯层通光截止厚度，而且当SiO₂－TiO₂芯层厚度为0.5 μm时，SiO₂下包层厚度至少有6μm才能防止1550 nm波长光泄露入单晶硅衬底中。制备的光波导对于1550 nm波长光传输损耗最小值为0．34 dB／cm。

SiO₂-TiO₂ planar optical waveguides were prepared with the sol-gel method. The thermal properties of SiO₂/TiO₂ sol-gel were analyzed with differential scanning calorimeter (DSC) and thermo gravimetric analysis (TGA). The morphologies of planar waveguides were characterized by SEM and AFM. The propagation loss of the planar optical waveguide at 1 550 nm was measured. The experimental results demonstrate that the gel thin film with the drying processing at 200 ℃ in 30 min presents the porous structure,and for the unsymmetrical planar waveguide,there is a light flux cut-off thickness for a core layer. When the thickness of SiO₂-TiO₂ core layer is 0.5 μm,the cladding thickness should be at least 6 μm to prevent 1550 nm light from propagating into the substrate of monocrystalline silicon. At present,the minimum propagation loss of the planar optical waveguides at 1 550 nm is 0.34 dB/cm.