玻璃基掩埋式光波导堆栈的制作与表征

Manufacturing and Characterization of Buried Optical Waveguide Stack in Glass Substrate

在硅酸盐光学玻璃基片上制作了光波导堆栈,这种光波导堆栈通过Ag+/Na+熔盐离子交换和电场辅助离子扩散技术顺次制作了两层掩埋式光波导.对光波导堆栈的横截面显微结构进行了观察,并对堆栈中两层波导的损耗特性进行了测试.所获得的光波导堆栈中的上、下两层波导芯部分别位于玻璃表面以下14和35μm处;上层光波导芯部尺寸约为12μm×7μm;下层光波导芯部尺寸约为9μm×8μm.通光测试显示两层波导在1.55μm工作波长下均为单模光波导,且两者之间没有相互耦合.损耗测试分析结果显示:堆栈中两层光波导的传输损耗均约为0.12 dB/cm,与单模光纤之间的耦合损耗分别为0.78和0.73 dB.分析表明,这种光波导堆栈在玻璃基集成光芯片的高密度集成方面具有很好的应用前景.

On silicate optical glass substrate, buried optical waveguide stacks were obtained. The stacks were com- posed of two layers of buried optical channel waveguide at different depth beneath the glass substrate surface, and each layer was manufactured by thermal Ag＋/Na＋ ion-exchange and field-assisted ion-diffusion. Microstructure of the optical waveguide chips was observed with optical microscope, and insertion loss of each layer in waveguide stacks is measured. Results show that the buried waveguide stack is composed of two layers of buried waveguide with their core center located at 14 μm and 35μm, respectively. Beneath the glass surface, core dimension of top layer and bottom layer waveguide are 12 μm× 7μm and 9 μm×8μm, respectively. Waveguides in both layers are single mode at operating wavelength of 1.55 μm. There is no directional coupling observed between waveguides at different layers. Insertion loss characterization indicates that propagation loss of both layers in the stack is 0.12 dB/cm, and coupling losses with single mode fiber are 0.78 dB/facet and 0.73 dB/facet, for top and bottom layer waveguides, respectively. The analysis suggests that this kind of optical waveguide stack is promising in application of high density integration of glass-based optical chip.