【作者】 耿鹏程；

【导师】 张伟刚；

【作者基本信息】 南开大学 ， 光学， 2013， 博士

【摘要】 随着众多类型光纤与光纤光栅的问世,单根光纤与光纤光栅对光波的调控能力几乎发挥到了极致,人们似乎只有通过复杂的光纤集成系统,才能实现对光波的进一步操控,然而,这显然与当前光纤器件微型化与集成化的发展趋势是相左的。按照新的物理观点,光纤技术在光波控制和光波信息交换等方面的内涵还远没有得到更深入的认识与挖掘,还有待于人们从不同的角度开展深入系统的研究。因此,本文基于空间调制理论和高频C02激光脉冲三维写制光栅技术,首次设计或研制出几种具有多重非对称特征的光纤与光纤光栅,并对其应用进行了相关研究和探索,为设计与研制具有灵活操控光波功能的新型光纤与光纤光栅提供了新理念和新方法。论文主要工作和研究成果如下：1.首次提出多重非对称光纤与光纤光栅的概念。根据光纤与光纤光栅的空间调制特征,首次较为系统的对光纤与光纤光栅的多重非对称性进行了分析和总结,丰富了现有光纤与光纤光栅的分类方法。2.首次较为系统的分析了非对称性对光纤导光性能的影响。分别从光纤横截面上纤芯的非对称性对纤芯模式导光特性的影响、包层的非对称性对局域包层模导光特性的影响、光纤轴向非对称性对超模模式间耦合特性的影响三个方面,对非对称光纤的导光特性进行了理论模拟和分析。3.通过选择性填充方法在一段保偏光子晶体光纤的非对称区域(两个大空气孔中)填入了折射率温敏匹配液,实现了光纤轴向和横截面的共同非对称填充调制,将填充后的光子晶体光纤内置于Sagnac环中,研制出一种新型温度传感器。提出的这种多重非对称填充方式,可以灵活调控光子晶体光纤内光波的传导特性,为新型光子晶体光纤调谐器件的研制提供了新思路和新方法。4.基于折射率匹配谐振耦合原理,设计-了一种带宽高达400nm的新型单偏振单模光子晶体光纤,该光纤具有可灵活调控纤芯模式和多个局域包层模式间耦合系数等特点。提出的设计方法,对新型光子晶体光纤的设计与研制具有重要的参考价值。5.首次提出一种双波段正交单偏振单芯光子晶体光纤,其两个正交偏振态分别支持1.31μm和1.55μm波段内光波的单偏振传输。这种新型双波段正交单偏振光纤具有独特的导光机制,为新型偏振光纤器件的研制以及解决光纤中偏振衰落问题提供了新理念和新方法。6.基于有限差分光束传播法设计了一种具有多重非对称结构的可调谐光纤耦合器。在1.40μm至1.70μm波段内,此种耦合器的输出分光比和工作波长可以灵活调节。此外,设计的光纤耦合器集成在一根长度仅为7.3mm的光纤中,这为光器件的全光纤化、微型化提供了新思路。7.首次设计并研制出一种具有折射率多重非对称调制结构的正交级联长周期光纤光栅。基于此新型光纤光栅,实现了一种构造简便、性能优异的二维弯曲矢量传感器,为单光纤光栅空间感测以及优化和提升光纤光栅调控光波的功能提供了新的实现途径。此外,基于此种光纤光栅的结构特征和弯曲传感特性,我们提出了一种三维正交传感坐标系,利用该坐标系可以方便的同时解调出弯曲方向和曲率大小。8.分析了倾斜长周期光纤光栅的多重非对称空间调制特性,建立了其理论分析模型。实验研究了倾斜长周期光纤光栅和超长周期光纤光栅的扭转传感特性,结果表明,倾斜长周期光纤光栅可用于新型扭转与温度双参数传感器的研制。9.设计了几种基于双偏芯和正-偏双芯光纤的多重非对称光纤光栅,把光纤的多重非对称空间调制与光纤光栅的多重非对称空间调制特性相结合,对其潜在应用进行了分析和探索,对新型功能集成光纤光栅的设计与研制具有极其重要的参考价值。更多还原

【Abstract】 With the advent of many types of optical fiber and optical fiber grating, the ability to regulate and control the light waves almost play to the extreme for a single fiber and fiber grating, it seems that people only through complex fiber integrated system for achieving further manipulate light, however, this is clearly contrary to the development trend of miniaturization and integration for fiber optic device. In accordance with the new physical point of view, the meaning of the optical fiber technology in light control and light information exchange also far more in-depth understanding and mining, in-depth research has yet to be carried out from different angles. Therefore, based on the theory of three-dimensional spatial modulation and the grating writing technology by frequency CO2laser pulses, we designed or developed several multiple asymmetric optical fiber and optical fiber grating for the first time, and research and exploration of their application, to provide new ideas and new methods for designing or developing new optical fiber and fiber grating which with the flexibility to manipulate light waves. The main contents and research results are as follows:1. We firstly proposed the concept of multiple non-symmetrical optical fibers and optical fiber grating. According to the spatial modulation characteristics of the optical fiber and fiber grating, we firstly systematic analysis and summary the multiple non-symmetry of the optical fiber and the optical fiber grating, enriching the existing classification of fiber and fiber grating.2. We firstly systematic analysis the performance of the fiber-optic light guide by the multiple non-symmetry. Respectively, how the core asymmetry on the fiber cross section impact on the performance of the fiber-optic light guide; how the clad cladding asymmetry on the fiber cross section impact on the performance of the fiber-optic light guide; how the axial direction asymmetry impact on the performance of the fiber-optic light guide, to theoretical simulation and analysis on the characteristics of the asymmetric optical fiber.3. We populated temperature sensitive refractive index matching fluid in asymmetric region of polarization-maintaining photonic crystal fiber by the selectivity fill method, achieving of common asymmetric filling modulation for the axial direction and cross-sectional of fiber. We developed a new type of temperature sensor by putting the filled photonic crystal fiber in Sagnac loop. We could flexibly regulation of the conduction properties of the light in the photonic crystal fiber by the proposed multiple asymmetric filling method, it provided new ideas and new methods for developing new type photonic crystal fiber tuning device.4. A new type broadband single-polarization single-mode microstructure fiber based on index-matching coupling is proposed by using the full vector finite-element method. The single-polarization single-mode operation bandwidth reaches400nm. The fiber has a flexible regulation of the core mode and more local cladding mode coupling coefficient. The proposed design method has an important reference value for designing and developing the new microstructure fiber.5. We firstly proposed a dual-band orthogonal single polarization single-core microstructure fiber. The light located in the1.31-and1.55-μm bands propagates through orthogonal polarization states in the proposed fiber. For a propagation distance of20mm, the20-dB bandwidth for the same x-or y-polarized modes within the1.31-and1.55-μm wavelength bands could, respectively, reach20.5and45.3nm, which is much wider than that of a two-core PCF.6. Based on the finite difference beam propagation method, we designed a multiple a tunable fiber coupler with the asymmetric structure. The operating wavelength of such a coupler can be adjusted in1.40μm to1.70μm band, and the output splitting ratio of the coupler can be adjusted at any wavelength. In addition, the designed optical-fiber coupler is integrated in a fiber with only7.3mm length. This provides a new idea for the all-fiber optical and miniaturization devices.7. A novel bending vector sensor based on spatial cascaded orthogonal long period fiber gratings (SCO-LPFGs) written by high-frequency CO2laser pulses has been proposed, and two-dimensional bending vector sensing characteristics based on the simple SCO-LPFGs have been experimentally demonstrated. A three- dimensional orthogonal sensing coordinates is established, and furthermore both of curvature and bending-direction could be intuitively solved according to the coordinates. To some extent, these studies would be improve the practicability of fiber vector sensor due to its simple, low-cost, ease of fabrication, and simple, precise, intuitive interrogation method.8. We analyzed the spatial modulation characteristics of multiple asymmetric tilt long period fiber grating, established the theoretical analysis model. Experimental study the twist sensing characteristics of tilt long period fiber grating and tilt Ultra-long period fiber grating. The results show that, tilt long period fiber grating can be used to the new twist and temperature two-parameter sensor.9. We designed several asymmetric double eccentric and center-side double cores fiber-based multiple asymmetric fiber grating. We combined of fiber multiple asymmetric spatial modulation and fiber grating multiple asymmetric spatial modulation characteristics, and analysis and explore its potential application. It has the extremely important reference value for designing and developing the new functional integration fiber grating.更多还原