【作者】 刘峰；

【导师】 符建；

【作者基本信息】 浙江大学 ， 光学工程（专业学位）， 2016， 硕士

【摘要】 扭转型高双折射光纤因其对圆偏振光的保偏能力,有着广阔的应用前景,可以广泛的应用在传感领域,比如电流互感器、光纤陀螺等方面。现在比较成熟的保偏光纤包括低双折射保偏光纤和高双折射保偏光纤。低双折射保偏光纤是通过降低光纤本身的双折射效应来保持光的偏振度,但是这种光纤对外部的环境非常的敏感,比如温度、外部应力等。而高双折射光纤是增强光纤本身的双折射效应,使外部因素可以忽略不计。目前一般所用的都是高双折射保偏光纤。但是我们在电流互感器中使用该光纤时需要将其缠绕在电流导体上,所以随之而来是应力区也会随之改变,那么经过准直进入的线偏振光也会随着应力区的改变,偏振特性发生变化,不能保持其完整的线偏振性。这时扭转型高双折射光纤就可以发挥重要的作用。扭转型高双折射光纤是在高双折射光纤的基础上以一定的扭转率扭转得来的,所以它本身的双折射效应可以使外部扭转所产生的影响忽略不计。相比于高双折射光纤,扭转型高双折射光纤还不需要精确的准直,使其在使用时更加的方便。随着人们对精确测量的要求越来越高,该种光纤将会得到更大的重视。但因为制造工艺上的难度,也使得它的发展比较缓慢。本文主要工作内容如下：1.从偏振理论出发,描述了光的偏振性,分析了偏振模色散对传输光偏振特性的影响。在通过对光纤耦合理论及扭转型高双折射光纤的理论研究,得出了该光纤的耦合模特性,被加工光纤的要求及温度对扭转型高双折射光纤的影响。2.完成了对扭转型高双折射光纤制备装置的设计,包括主要元器件的选型,机械结构的设计,加热方式的确定,控制系统的软硬件设计。3.通过对扭转型高双折射光纤制备装置的实验及扭转型高双折射光纤的性能测试,不断提出系统的改进方案,并且得到了在该系统下最佳的加工参数并创新的提出了新的加工方式。更多还原

【Abstract】 Spun Hi-Bi Fiber is able to maintain the polarization of circularly polarized light, which offers a bright future for its application. It can be widely applied to the sensing field, in such aspects as current sensor, fiber-optic gyroscope, and etc. The polarization-maintaining optical fiber that is relatively fully developed today includes low birefringence polarization-maintaining optical fiber and high birefringence polarization-maintaining optical fiber.1) Low birefringence polarization-maintaining optical fiber:it diminishes its influence on polarization property by lowering the birefringence effect of the optical fiber itself, but it is quite sensitive to the external environment such as the change of temperature and of the external stress.2) High birefringence polarization-maintaining optical fiber:it strengthens its own birefringence effect, making the external factors ineffective. The commonly used polarization-maintaining optical fiber, at present, is the latter one. However, the high birefringence polarization-maintaining optical fiber needs to be twined at current conductor when used at current sensor. As a consequence, its corresponding stress region will be turned and changed. Consequently, the linear polarized light will change as the change happening in the stress region and in the polarization property. This makes it unable to maintain its linear polarization resistance stable.Under this circumstance, Spun Hi-Bi Fiber is able to play a vital role. Based on high birefringence optical fiber, it is reversed through a certain rate of reverse. Thus its internal birefringence effect can result in the ineffectiveness of the influence caused by the external reverse. Compared with high birefringence polarization-maintaining optical fiber, Spun Hi-Bi Fiber does not need precise collimation, which increases convenience when used. With the increasingly higher requirement of precise measurement, Spun Hi-Bi Fiber will be attached greater importance to. Nevertheless, the difficulties in its manufacturing technique hinder its development.The main contents of this article are as follows:1. It describes the polarization property of light, analyzes polarization mode dispersion’s effect on it from the perspective of the polarization theory. Based on the study of the theory of the spun Hi Bi Fiber, the following results can be gained:the coupling model of the optical fiber, the request on optical fiber processed and the influence of temperature on the spun Hi Bi Fiber.2. Complete the design of the preparation device of spun Hi Bi Fiber, including the selection of main components, the design of mechanical structure, the determination of heating method and the design of hardware and software of the control system.3. Through the experiment on the preparation device of spun Hi Bi Fiber and the test done in spun Hi Bi Fiber, systematic improvement projects are carried out continually. Also, from this device, the best machining parameters are gained and new processing modes are creatively put forward.更多还原