光波导化学传感技术研究
文献类型：学位论文
| 作者 | 初凤红 |
| 学位类别 | 博士 |
| 答辩日期 | 2008 |
| 授予单位 | 中国科学院上海光学精密机械研究所 |
| 导师 | 瞿荣辉 |
| 关键词 | 集成光学 波导环形谐振腔 溶胶－凝胶 溶解氧 荧光猝灭 |
| 其他题名 | Study on optical waveguide chemical sensor |
| 中文摘要 | 光波导化学传感器具有体积小、重量轻、灵敏度高、抗电磁干扰、便于集成等优点，在化学传感领域中占有越来越重要的地位。发展新的传感技术，降低传感成本是目前光波导化学传感领域研究的热点之一。本论文利用低成本的溶胶－凝胶技术制备条波导和波导环形谐振腔，对波导环形谐振腔的特性进行了理论分析，采用简单的条波导Sagnac环和波导环形谐振腔进行气体传感。并用溶胶－凝胶技术制备敏感材料，开发了一套基于荧光猝灭效应的溶解氧传感系统。本文的主要内容包括以下几个方面： 环形谐振腔Q值较高，用作传感时，有很高的灵敏度。本论文首先从传输矩阵出发，分析了波导环形谐振腔的传输特性；讨论了波导参数及工作波长等因素对环形腔传感时灵敏度的影响，为设计和制作环形谐振腔传感器打下了基础；并对有源波导环形谐振腔在传感和产生毫米波方面的应用进行了分析。 利用溶胶－凝胶法制备条波导和波导环形谐振腔。溶胶－凝胶条波导的多孔结构在吸收了气体后双折射会发生变化，利用这一特性，提出了一种简单的传感结构：将条波导接入光纤Sagnac环中，利用条波导的双折射随乙醇蒸汽浓度变化而变化的特性测量乙醇蒸汽的浓度。采用Jones矩阵方法，分析了条波导Sagnac结构的输出特性，并给出了解析表达式。测量了不同浓度乙醇蒸汽下的透射光功率，发现二者变化呈正弦关系。实验中发现条波导的双折射与乙醇蒸汽浓度呈亚线性关系，从实验数据拟合得到所制备的条波导的双折射对乙醇浓度的响应为 ，测量了信号变化的时间演变特性，典型的上升和下降时间常数分别为3min和12min。 波导环形谐振腔的高Q值决定了其在传感时的高灵敏度。利用环形谐振腔谐振波长随周围气体浓度的变化而移动的特性进行挥发性有机化合物传感。测量了在不同物质、不同浓度的挥发性有机化合物蒸汽气氛下波导环形谐振腔的传输光谱的敏感性。发现谐振波长随甲醇、乙醇、丙醇等醇类化合物，以及丙酮、甲醛等蒸汽浓度的上升而向长波方向移动，具有高的灵敏度；发现两者基本上呈线性关系。其中，对丙醇最敏感，灵敏度达到1.403pm/ppm。对甲烷和二甲苯也有微弱反应，但是灵敏度很低。也测量了水蒸汽对传输谱特性的影响。论文对于敏感性的机理进行了讨论。 在进行上述工作的同时，还开发了一套利用荧光猝灭效应进行溶解氧传感的实验装置。采用邻啡咯啉钌作为荧光指示剂，用上述的溶胶－凝胶法制备用于溶解氧传感的敏感材料，选用聚甲基丙烯酸甲脂塑料光纤作为传光和传感原件，将传感头做成U型以提高灵敏度，通过荧光寿命与溶解氧浓度的关系来测量水中溶解氧的浓度。实验测得荧光寿命与溶解氧浓度之间并不符合S-V方程，而是呈现亚线性关系，提出了双层模型来解释这一实验现象。实验研究了U型光纤弯曲半径、荧光物质邻啡咯啉钌浓度和敏感材料的退火时间对系统灵敏度的影响。 |
| 英文摘要 | Optical chemical sensors have become more and more important in chemical sensor areas; they have many advantages such as small volume, light weight, high sensitivity, immune to electromagnetic interference, easy integration. Developing new sensor technology, lower cost has become hotspot in optical chemical sensing technology. In this dissertation, low cost sol-gel technology was used to fabricate strip waveguide and ring resonator, optical ring resonstor’s transmission characteristic was analyzed theoreticly; strip waveguide Sagnac ring and ring resonator were used to measure gases; we also used sol-gel technology to fabricate oxygen sensitive material and developed a dissolved oxygen sensor system based on fluorescence quenching effect . The main contents of this dissertation are listed below: Optical ring resonator has high sensitivity in sensing area due to its’ high Q factor. Waveguide ring resonator’s transmission characteristic was analyzed based on transmission matrix, when the ring resonator was used in sensing area, the relationship between waveguide parameters, working wavelength and sensitivity was analyzed, which laid the foundation for designing and fabricating ring resonator; the usages of active ring resonator in sensing and producing millimeter wave were also studied. Sol-gel technology was used to fabricate strip waveguide and ring resonator. Strip waveguide’s birefringence will change when absorbing ambient gas, based on this characteristic a simple sensor structure was introduced: the strip waveguide was connected into a Sagnac fiber loop, birefringence character of strip waveguide was used to detect ethanol vapor. Jones matrix was used to analyze the output characteristic of channel waveguide Sagnac ring. Output signals from the loop were measured under environment of different ethanol vapor concentrations. The relationship between birefringence and ethanol concentration is sublinear and the birefringence sensitivity to ethanol concentration was evaluated to be . Temporal response was also measured, and the rising and falling time constant were obtained to be 3min and 12min respectively. In this dissertation ring resonator was used to detect volatile organic compound (VOC) due to its high sensitivity, Ring resonator resonant peak will shift with different vapor concentration. Sensitivities of ring resonator transmission spectrum were measured under different concentrations of different VOC. It was found that the resonant peak shifted towards longer wavelength with the concentration of methanol, ethanol, propyl alcohol, acetone and formaldehyde with high sensitivities and linear relations. Among them, the device has highest sensitivity to propyl alcohol with sensitivity 1.403pm/ppm. The device was found to have weak reaction to xylene and methane. The influence of water vapor to the spectrum was also measured. Mechanisms of the sensitivity were discussed in the paper. Meanwhile, a dissolved oxygen sensor based on fluorescence quenching was developed. Dichlorotris (1, 10-phenanthroline) ruthenium ( [Ru (dpp)3]2+) was used as an oxygen indicator, sol-gel method was used to make sensor material, and plastic optical fiber for delivering the excitation light and picking-up the longer wavelength fluorescence radiation, the sensor head was bent to U shape to enhance sensitivity. Dissolved oxygen concentration wad detected by measure fluorescence lifetime. It was found experimentally that the obtained characteristics showed deviation from linear relation described by commonly used Stern-Volmer equation. A two-layer model is proposed to explain the phenomena. The effect of oxygen indictor concentration, sol-gel film annealing time and U-shape POF curve radius on the system sensitivity were also studied. |
| 语种 | 中文 |
| 源URL | [http://ir.siom.ac.cn/handle/181231/15241]  |
| 专题 | 上海光学精密机械研究所_学位论文 |
| 推荐引用方式 GB/T 7714 | 初凤红. 光波导化学传感技术研究[D]. 中国科学院上海光学精密机械研究所. 2008. |
入库方式： OAI收割
来源：上海光学精密机械研究所
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