【作者】 贾宏志；

【导师】 李育林；

【作者基本信息】 中国科学院西安光学精密机械研究所 ， 光学， 2001， 博士

【摘要】 本文对光纤光栅传感器的基本理论和技术进行了系统的研究，主要内容包括：光纤光栅的耦合模理论分析；光纤光栅的制作方法；光纤光栅的传感机理；光纤光栅的温度、压力增敏及去敏方法；光纤光栅传感器用宽带光源的研制及光纤光栅波长解调技术。 首先对光纤光栅传感器的研究现状和发展趋势进行了回顾和展望。按照理想波导模展开法推导了模式耦合方程，并用耦合模理论详细研究了光纤Bragg光栅和啁啾光栅的反射特性（反射带宽和峰值反射率）与光纤光栅的参数（光栅长度、耦合系数、啁啾系数等）之间的关系。提出了一种饱和情况下光纤Bragg光栅折射率分布的数学模型，利用该模型研究了饱和情况下Bragg光栅的一、二阶衍射特性，模拟了Bragg光栅一、二阶衍射的形成过程，模拟结果与实验数据吻合的很好。 光纤光栅的制作技术是其批量生产和广泛应用的关键。本文系统论述了光纤光栅的各种制作方法并比较了各种制作方法的优缺点。重点对相位掩模法进行了讨论，采用标量衍射理论分析了相位掩模的近场衍射特性，研究了写入光正入射和斜入射条件下的成栅特点，得出了一些重要结论。进行了用相位掩模制作光纤Bragg光栅的实验研究。 系统研究了光纤Bragg光栅和长周期光栅对温度、应变及压力的传感机理。分析了Bragg光栅的二阶温度、应变灵敏度和温度-应变交叉灵敏度对测 摘 要一量结果的影响。详细研究了Brngg光栅的温度增敏和去敏以及压力增敏的方法和原理。此外，还详细论述了光纤光栅同时测量温度和应变的各种方案，对各，种方案的优缺点进行了分析比较，并分析了各种方案的系统误差。对光纤Bragg。光栅的温度、应力传感特性进行了实验研究，在25”C～100”C的温度范围和0－809的应力范围内测出了Bragg光栅的波长－温度和波长－应力响应曲线。 宽带光源和波长解调是光纤光栅传感器在实际应用中必须解决的问题，我们研制了多种半导体激光器驱动电源和半导体激光器冷却系统，合作研制了采用掺饵光纤的宽带光源。本文还论述了光纤光栅的波长解调方法，包括匹配光栅法、可调谐法布里－琅罗腔法、非平衡MachZehnder于涉仪法和可调谐光源法等，提出了一种解调光纤光栅波长的可调谐法布里－琅罗腔结构并计算了法布里－琅罗腔的参数。更多还原

【Abstract】 This thesis focuses on the basic theoretical and technical researches on the optical fiber grating sensors, including coupled mode analysis of optical fiber gratings; the fabrication methods of optical fiber gratings; the sensing mechanism of fiber gratings; the increasing and decreasing of temperature and pressure sensitivities of optical fiber gratings, the fabrication of wide band light source for fiber grating sensors and the demodulation technologies for the wavelength signals of fiber grating sensors. Firstly, the recent developments in the area of optical fiber grating sensors are reviewed. The coupled mode equations are built by means of expanding perfect waveguide modes. Using the coupled mode theory, the relationships between the reflective spectrum characteristics of fiber Bragg gratings and chirped gratings (the maximum reflectivity and the bandwidth) and their structural parameters (grating length, coupled coefficient, chirped coefficient, etc.) are studied. A mathematical model about refractive index distribution of fiber Bragg gratings under saturation is ? proposed Using this model, the first- and second-order diffraction characteristics of fiber Bragg gratings under saturation are studied and the formation processes of the first- and second-order diffraction are simulated. The simulated results are in excellent agreement with the experimental results Supported by Chinese National Nature Science Foundation (No. 69878001) ?? ~~1 The key problem of optical fiber gratings to be wide application and batch production is the techniques of fiber grating fabrication. In this thesis, various fabrication methods of fiber gratings are described systematically. The advantages -~ and disadvantages of each method are analyzed and compared. The research work mainly focuses on the phase mask method. The characteristics of near field diffraction of the phase mask are analyzed with scalar diffraction theory. The properties of grating formation are studied specifically when the writing light beam incidents normally and slantingly, respectively. Some important conclusions are obtained. The experimental study is accomplished to fabricate the fiber Bragg gratings with phase mask. The temperature, strain and pressure sensing mechanisms of fiber Bragg gratings and long-period gratings are studied systematically. The influences on the measurement results caused by the second-order temperature and strain sensitivities as swell as temperature-strain cross sensitivity are analyzed. The methods and mechanisms of increasing and decreasing of temperature sensitivity as well as increasing of pressure sensitivity are also studied In addition, various schemes of simultaneously measuring strain and temperature with fiber grating sensors are described. The advantages and disadvantages of these schemes are compared. The systematic errors of these schemes are also discussed. The temperature and stress sensing characteristics of fiber Bragg gratings are studied experimentally. The response curves of wavelength-temperature and wavelength-stress are measured in the range of 250C-1000C and O?80g, respectively. Broad band light source and wavelength demodulation technologies are two更多还原