Conventional silica optical fibers can be embedded into composite structures or packaging to provide structural monitoring capabilities. In this paper, the microbending optical losses induced by the packaging of a sensing optical fiber into a sandwiched glass-fiber reinforced structure are investigated experimentally and by simulations. Results show that the positioning of the optical fiber within a plain-weave glass fiber-reinforced structure has a critical effect on microbending optical losses due to potentially induced microdeformations of the optical fiber's cylindrical shape. Similar analysis is also carried out with the use of a 1D glass-fiber layer packaging, demonstrating lower residual microbending losses after manufacturing. By the proper positioning of an optical fiber containing a series of wavelength-multiplexed fiber Bragg grating (FBG) sensors over a 2D plain-weave glass fabric, a 10-fold improvement in the induced optical losses is demonstrated, increasing the optical power that reaches the interrogating unit and allowing the monitoring of hundreds of meters over glass-fiber structures. Although all the analysis is focused and verified using a series of FBG sensors, the results and conclusions related to the induced microbending losses are also valid and useful for distributed optical fiber sensing approaches.

中文翻译：

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评估和最小化嵌入到玻璃纤维复合材料中的光纤传感器中的诱导微弯损耗

传统的石英光纤可以嵌入复合结构或包装中，以提供结构监测功能。在本文中，通过实验和模拟研究了将传感光纤封装到夹层玻璃纤维增​​强结构中引起的微弯曲光损耗。结果表明，光纤在平纹玻璃纤维增​​强结构内的定位对微弯光学损耗具有关键影响，因为光纤的圆柱形可能会引起微变形。使用一维玻璃纤维层封装也进行了类似的分析，证明制造后的残余微弯损失较低。通过将包含一系列波长多路复用光纤布拉格光栅 (FBG) 传感器的光纤正确定位在 2D 平纹玻璃织物上，诱导光损耗提高了 10 倍，增加了达到的光功率询问单元并允许在玻璃纤维结构上监测数百米。尽管使用一系列 FBG 传感器集中和验证了所有分析，但与感应微弯损耗相关的结果和结论对于分布式光纤传感方法也是有效和有用的。增加到达询问单元的光功率，并允许在玻璃纤维结构上监测数百米。尽管使用一系列 FBG 传感器集中和验证了所有分析，但与感应微弯损耗相关的结果和结论对于分布式光纤传感方法也是有效和有用的。增加到达询问单元的光功率，并允许在玻璃纤维结构上监测数百米。尽管所有分析都集中在使用一系列 FBG 传感器进行验证和验证，但与感应微弯损耗相关的结果和结论对于分布式光纤传感方法也是有效和有用的。