摘要
利用射频溅射技术在平面单模玻璃波导表面局部淀积一层Ta_2O_5梯度薄膜,形成复合光波导芯片,结合棱镜耦合法制备了一种集成光偏振干涉传感器.基于四层平板波导模型理论分析了复合光波导表面折射率灵敏度S_(RI)与Ta_2O_5梯度薄膜等效厚度T_(eq)的关系,结合实验测定的S_(RI)得出了本工作中所使用Ta_2O_5梯度薄膜的T_(eq)≈33.021 nm,进一步得出芯片吸附层厚度灵敏度S_(ad)≈(2.412×2π)nm^(-1).利用该复合波导偏振干涉仪结合Lorentz-Lorenz有效介质理论测得了市售食用白醋中醋酸的浓度,并以市售牛栏山二锅头洒为例进行了白酒掺水和掺甲醇的测试,结果表明,白酒掺水或甲醇前后的折射率改变量与掺杂量成准线性变化关系;原位实时监测了丁酰胆碱酯酶的动态吸附过程及细胞色素c/聚苯乙烯磺酸钠的分子自组装过程,并利用测得的位相差变化结合芯片吸附层厚度灵敏度S_(ad)获得了蛋白质表面覆盖度.
A tapered thin film of Ta2O5 is sputtered on a single-mode slab glass waveguide to form a composite optical waveguide（COWG） for serving as a prism-coupled integrated optical polarimetric interferometer.The relationship between the refractive-index sensitivity （Sri） of the interferometer and the equivalent thickness（Toq） for the tapered layer of Ta2O5 is theoretically analyzed based on a fourlayer homogeneous waveguide model.A comparison of the measured Sri with the simulated data leads to Teq≈33.021 nm for the COWG used.The sensitivity of the interferometer to thickness of the protein adlayer is determined to be Sad≈（2.412×2n）/nm. The acetic-acid concentration of a commercial Chinese vinegar is investigated,for the first time,by use of the interferometer combined with the Lorentz-Lorenz effective-medium theory.Water and methanol adulterations of a commercial Chinese liquor are detected with the interferometer.The results indicate that the refractive-index change induced by the adulteration is a quasi-linear function of the adulteration amount.Both the dynamic adsorption process of butyrylchohnesterase and the self-assembly process of cytochrome c/PSS multilayer film are monitored in real time with the sensor.The protein surface coverage is obtained from the combination of the measured phase-difference change and the adlayer-thickness sensitivity.
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
2012年第11期319-326,共8页
Acta Physica Sinica
基金
国家自然科学基金(批准号:60978042,61078039)
国家重点基础研究发展计划(批准号:2009CB320300)
中国科学院百人计划基金资助的课题~~
关键词
复合光波导
偏振干涉
高灵敏度
生化检测
composite optical waveguide； polarimetric interferometry； high sensitivity； chemical biosensing
