基于热极化双孔光纤的电调谐光开关的研究

发布时间：2018-03-02 10:37

本文关键词： 热极化光纤开关调谐二阶非线性　出处：《北京交通大学》2016年硕士论文　论文类型：学位论文

【摘要】：石英玻璃材料是一种无定型的非晶体材料,结构上具有宏观反演对称性,使得它不具有偶数阶光学非线性极化率,热极化打破了结构的对称性,诱导出永久稳定的二阶非线性。本文提出了基于热极化双孔光纤的电调谐光纤光栅,并实验实现了基于热极化双孔光纤的Mach-Zehnder电调谐光开关。基于二维双载流子模型,结合热极化后电场在双孔光纤横截面的分布情况,得到了热极化后折射率的改变情况。应用紫外光在热极化光纤二阶非线性周期性擦除效应,可以实现基于热极化双孔光纤的电调谐光纤光栅。系统研究了一定电压下初始折射率差、光栅长度对反射率的影响。实验搭建了基于热极化双孔光纤的Mach-Zehnder电调谐光开关。Mach-Zehnder干涉仪主动臂由热极化处理的双孔光纤构成。实验结果表明,首次极化后,耗尽层未覆盖纤芯,纤芯主要由反向电场覆盖。在这种情况下,在双孔光纤热极化阴极端施加外加电压时开关电压较小。二再次热极化后,纤芯中耗尽层发生变化,此时纤芯由正反向电场同时覆盖,当外加电压再次施加在热极化阳极端时的开关电压较小。本文实验验证了反向电场的存在,并且首次利用反向电场实现了基于热极化光纤的Mach-Zehnder干涉仪的开关作用。基于热极化双孔光纤的全光纤电光开关无需光电转换,具有较低的插入损耗、较高的消光比和较高的开关速度,本文研究的热极化光纤电调谐光开关对热极化光纤在全光纤器件的应用方面提供了参考。
[Abstract]:Quartz glass material is an amorphous material, which has macroscopic inversion symmetry in structure, so it does not have even order optical nonlinear polarizability. Thermal polarization breaks the symmetry of structure. In this paper, an electrically tuned fiber grating based on thermally polarized double-hole fiber is proposed, and the Mach-Zehnder electrically tuned optical switch based on thermally polarized double-hole fiber is experimentally realized. The change of refractive index after thermal polarization is obtained by combining the distribution of electric field after thermal polarization in the cross section of two-hole fiber. The second order nonlinear periodic erasure effect of ultraviolet light is applied to the thermal polarization fiber. The electrically tuned fiber grating based on thermally polarized double-hole fiber can be realized. The initial refractive index difference at a certain voltage is studied systematically. The effect of grating length on reflectivity. The Mach-Zehnder electrically tuned optical switch .Mach-Zehnder interferometer active arm based on thermally polarized double-hole fiber is constructed. The experimental results show that the depletion layer does not cover the core after the first polarization. The core is mainly covered by a reverse electric field. In this case, the switching voltage is smaller when the applied voltage is applied at the extreme of the thermal polarization negative of the double-hole fiber. After the second thermal polarization, the depletion layer in the core changes. At the same time, the core is covered by a positive and negative electric field, and the switching voltage is smaller when the applied voltage is applied again to the extreme of the thermally polarized positive. The existence of the reverse electric field is verified by experiments in this paper. The switch of Mach-Zehnder interferometer based on thermally polarized fiber is realized by reverse electric field for the first time. The all-fiber electro-optic switch based on thermally polarized double-hole fiber does not need photoelectric conversion and has low insertion loss. With higher extinction ratio and higher switching speed, the thermo-polarization fiber electrically tuned optical switch studied in this paper provides a reference for the application of thermal polarization fiber in all optical fiber devices.
【学位授予单位】：北京交通大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TN253

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