Huang S, Ohn M M, Measures R M
Appl Opt. 1996 Mar 1;35(7):1135-42. doi: 10.1364/AO.35.001135.
A strain-distribution sensing technique based on the measurement of the phase spectrum of the reflected light from a fiber-optic Bragg grating is described. When a grating is subject to a strain gradient, the grating will experience a chirp and therefore the resonant wavelength will vary along the grating, causing wavelength-dependent penetration depth. Because the group delay for each wavelength component is related to its penetration depth and the resonant wavelength is determined by strain, a measured phase spectrum can then indicate the local strain as a function of location within the grating. This phase-based Bragg grating sensing technique offers a powerful new means for studying some important effects over a few millimeters or centimeters in smart structures.
描述了一种基于测量光纤布拉格光栅反射光相位谱的应变分布传感技术。当光栅受到应变梯度作用时，光栅会经历啁啾，因此谐振波长将沿光栅变化，导致与波长相关的穿透深度。由于每个波长分量的群时延与其穿透深度相关，且谐振波长由应变决定，因此测量得到的相位谱可以将局部应变表示为光栅内位置的函数。这种基于相位的布拉格光栅传感技术为研究智能结构中几毫米或几厘米范围内的一些重要效应提供了一种强大的新方法。
