Stress and modal birefringence of single-mode specialty optical fibers with three-stress regions

Stress-induced birefringence and modal birefringence of single-mode specialty optical fibers with three stress regions are numerically analyzed by the vector finite element method. Stress distribution and stress-induced birefringence distribution of three kinds of optical fibers with different cross structures are presented and compared, and the influence on the stress-induced birefringence by temperature change are analyzed as well. The results show that the fibers with three-stress regions have a lower linear birefringence, which is very important for the fabrication of the circular polarization-maintaining fiber with high performance drawn from the same fiber preform by using the spinning method.     

非线性光纤光学研究型综合实验的设计与实践

非线性光纤光学是光学中广受关注的研究领域和前沿交叉学科。针对光学专业本科生,设计了非线性光纤光学研究型综合实验,内容包括文献调研、自主选题、实验装置搭建、实验结果分析以及实验内容拓展五个部分。实践证明,该研究型综合实验有助于锻炼学生的专业技能、开阔学生的学术视野、培养学生的创新意识和探究精神。     

碳纤维片材加固技术在某工程框架梁抗剪加固中的应用

粘贴碳纤维片材加固技术是一项新的应用外粘高性能复合材料加固结构的技术．碳纤维片材重量轻、高强度、高弹性、高耐久性，易于施工，现已开始应用于各类混凝土结构的加固处理．本文根据工程实际情况，简要介绍了碳纤维片材加固技术在混凝土框架梁抗剪加固工程中的应用．     

Mechanical analysis and reasonable design for Ti-Al alloy liner wound with carbon fiber resin composite high pressure vessel

To consider the internal pressure loaded by both the cylindrical Ti-Al alloy liner and the carbon fiber resin composite （CFRC） wound layers, two models are built. The first one is a cylinder loaded with the internal pressure in the hoop direction only. In this model, the total hoop direction load is distributed over all layers under the internal pressure. The second one is a cylinder loaded with the internal pressure in the axial direction only. In this model, the total axial load is distributed over all cylinders under the internal pressure. Taking the boundary conditions of the continuous displacement between layers into account, a group of equations are built. From these equations, we get the solutions of stresses in both hoop direction and axial direction loaded by every layer under internal pressures. After the stresses are obtained, a reasonable design can be done. An example is given in the final section of this study.