基于微纳光纤耦合器表面修饰的环境传感特性研究

With the continuous improvement of the fluence level of high-power laser, organic contaminants have been known to degrade the performance of optics components, which leads to laser-induced damage sometimes. In the project, bases on the high sensitivity of microfiber devices to refractive index of surrounding environment, surface modification microfiber coupler is proposed to monitor trace contaminants in high-power laser. Output output response at different environment, the relationship between contaminants concentration and spectra shift is investigated. Kinetic model of adsorption and desorption between material and surface modification are established. By investigating mechanism of the interaction of contaminants and surface modification film, impacting sensing unit performance law under the conditions of structure parameters, film parameters and film modification controlling condition and so on is obtained. Based on offline platform, benchmarking verification by using of partial pressure method, and seek to external environment such as polarization, temperature and humidity on the influence of sensing unit. Robustness, repeatability and stability of sensing unit is investigated. The application prospect of the new sensor in semiconductor manufacture, biosensor and so on is explored.

高功率激光装置光通量的不断提升，对光学元件的负载能力也提出了越来越高的要求，由装置内部空间中有机污染所引起的损伤问题逐渐浮现。本项目基于微纳光纤器件对外界环境折射率高度灵敏特性，提出了利用表面修饰微纳光纤耦合器在线监测高功率激光装置内微量污染物。研究不同环境下输出光谱响应，微量污染物浓度与光谱偏移量之间的对应关系；建立表面修饰膜层与污染物吸附与解吸附的动力学模型、优先吸附模型，通过研究表面修饰膜层与污染物相互作用机理，获取结构参数、膜层参数，膜层修饰控制条件等多场耦合下影响传感单元性能的规律；通过搭建离线验证平台，利用分压法对传感单元进行对标验证，并寻求外界环境例如偏振态、温度及湿度对传感单元的影响规律；利用在线验证平台，诠释传感单元的鲁棒性、可重复性以及稳定性。探索该环境传感器在其它方面的应用，例如生物传感，半导体制造等方面。

分子态有机污染成为影响高功率激光装置负载能力的关键因素之一，实现对装置内分子态有机污染物的在线监测可以保证装置的稳定运行、提高运行效率及降低运行成本。本项目基于微纳光纤强倏逝场的特性研究了表面修饰微纳光纤耦合器的有机污染物传感特性，并对其进行离线定标验证。首先，利用微纳光纤制备平台获得不同尺寸的单根微纳光纤，通过对其表面修饰，诠释不同尺寸、不同表面厚度等因素在不同有机污染物浓度下对单根微纳光纤传感单元的影响规律；其次，利用光传输法BPM（Beam Propagation Method，BPM）分析表面复合折射率变化对微纳光纤耦合器输出光谱的影响；最后，制备表面修饰微纳光纤耦合器传感单元，获得在不同气氛下及不同温度下传感单元对不同污染物浓度的响应特性，为装置内的微量污染物的在线监测提供了一种有效可靠的方法。