To meet the simultaneous requirement of high sensitivity and high measurement range is an uphill task in the development of fiber Bragg grating (FBG) strain sensor. A unique scheme of highly sensitive FBG strain sensor is proposed based on nonlinear four wave mixing (FWM) with a high measuring range. In this paper, both the edges of FBG reflection spectrum are used without increasing the number of sources. The FWM products generated are tuned to the reflection edges of the FBG. The signals reflected from the edges of the FBG are then utilized in the subsequent FWM process to enhance the sensitivity of the system. The proposed scheme can provide a strain measurement range of $2310\,\mu \epsilon $ with strain sensitivity of 91.21 dBm/nm.

中文翻译：

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基于高阶 FWM 的具有增强测量范围的高灵敏度 FBG 应变传感器

同时满足高灵敏度和高测量范围的要求是光纤布拉格光栅（FBG）应变传感器开发中的一项艰巨任务。基于大测量范围的非线性四波混频(FWM)，提出了一种独特的高灵敏度FBG应变传感器方案。在本文中，在不增加光源数量的情况下，使用了FBG反射光谱的两个边缘。生成的 FWM 产品被调谐到 FBG 的反射边缘。从 FBG 边缘反射的信号随后用于后续 FWM 过程，以提高系统的灵敏度。所提出的方案可以提供$2310\,\mu\epsilon $的应变测量范围，应变灵敏度为91.21 dBm/nm。