中文摘要：

光纤光栅是光纤传感和光纤通信领域的重要器件之一,光纤光栅的级联因其特性新颖一直是研究的热点。着重介绍了光纤布拉格光栅-长周期光纤光栅（FBG-LPG）级联结构在包层模式再耦合、边缘滤波和独立级联3方面的研究进展,讨论了各自的技术难点,并提出了改进意见。针对透射型FBG-LPG光路复杂的问题,提出一种反射型FBG-LPG独立级联结构,简化了光路,优化了系统性能,并进行了实验验证。在此基础上展望了FBG-LPG级联结构的发展趋势。

英文摘要：

Optical fiber gratings have become one of the most important devices in the field of optical fiber sensing and optical fiber communication. Because of the novel characteristics, cascaded structures of the fiber gratings have always been the focus of research. The research progresses of cladding mode recoupling, edge filtering and independent cascading of the fiber Bragg grating-long period fiber grating （FBG-LPG） cascaded structure are summarized, and their technical difficulties are discussed. Suggestions for improvement are presented. To address the problem o- the complexity of transmission type FBG-LPG optical path, a reflection type FBG-LPG independent cascaded structure which can effectively simplify the structure is proposed, and the system performance is optimized and verified by experiment. The development trend of the FBCr-LPG cascaded structure is predicted.