The Research Of Spun Hi-Bi Fiber And Its Manufacturing Device

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.