摘要
利用标准光刻工艺结合钾-钠离子交换技术,在玻璃基板上制备了一对间隔75μm的平行三维单模光波导通道。然后利用射频溅射方法在一条通道的中间区段淀积一层厚度小于30 nm的梯度TiO2薄膜,形成复合光波导。基于梯度耦合理论,横电基模能够低损失地穿过TiO2薄膜覆盖区间,并在该区间产生一个高强度消逝场。因此复合光波导可作为杨氏干涉计的敏感臂而裸露通道用作参比。线偏振氦氖激光通过棱镜耦合方式被同时输入到两通道中,由另一棱镜从两通道中耦合输出的光束相互重叠而产生明暗相间的空间干涉条纹。利用可调狭缝-光电探测器组合实现了对干涉计信号的实时探测。这种结构新颖的集成光杨氏干涉计可用于生化物质的超痕量探测。
Two parallel three-dimensional single-mode channel waveguides spacing of 75 μm were prepared on glass substrate by standard photolithography combined with K＋-Na＋ ion exchange.By use of sputtering technique,a tapered film of TiO2 with thickness 30 nm was then deposited on the middle region of one channel to form a composite optical waveguide.On the basis of the tapered velocity coupling theory,the fundamental transverse electric mode can propagate through the TiO2-covered region with a low attenuation,leading to a significantly enhanced evanescent field in this region.Therefore,the composite waveguide can serve as the sensing arm and the naked channel waveguide as the reference.With the prism-coupling method the linearly polarized He-Ne laser light was simulatenously launched into the two channels,and the divergent light emitted from the two channels are superposed to yield the Young′s interference pattern.The interferometer signal was interrogated using a slit-photodetector system.Such a novel integrated optical Young interferometer is applicable to the ultra-trace detection of chemical and biological measurands.
出处
《中国激光》
EI
CAS
CSCD
北大核心
2010年第3期819-821,共3页
Chinese Journal of Lasers
基金
中国科学院"百人计划"择优支持项目
国家973计划(2009CB320300)资助课题
关键词
集成光学
杨氏干涉仪
复合光波导
传感器
integrated optics
Young interferometer
composite waveguide
sensor
