Semicomputational calculation of Bragg shift in stratified materials
Semicomputational calculation of Bragg shift in stratified materials
复制标题
分层材料中布拉格位移的半计算计算
DOI：
10.1103/physreve.104.055307
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发表时间：
2021-11-18
影响因子：
2.4
通讯作者：
Passian, Ali
中科院分区：
文献类型：
--
作者：
Frey, Benjamin;Snyder, Patrick;Passian, Ali
光纤布拉格光栅(FBG)由于受到光纤芯介质材料的周期性空间扰动，可以看作是一维光子带隙晶体。与支持Bloch波的介质类似，雕刻的弱折射率调制为光纤的入射导模光子提供了一个周期性的“势”，产生了有用的光谱特性，这些特性已经成为传感应用和出现量子压缩和孤子的基础。FBG传感器对任意外界刺激的响应是一个多物理问题，没有已知的解析解，尽管FBG在经典和量子传感和计量中的应用越来越多。在这里，我们通过首先提出层状材料的热和弹性状态的固体力学模型来研究这一问题。该模型考虑了代表布拉格光栅的嵌入光学材料域，在这里以FBG的形式存在。利用该模型的输出，我们计算了光学模式以及它们的温度和应力诱导行为。该模型适用于任意形状和组成的介质，包括软物质和具有非线性弹性和几何非线性的材料。最后，我们利用计算的表面应力和温度分布来解析地计算布拉格位移，其结果与我们的实验测量结果符合得很好。
The fiber Bragg grating (FBG) may be viewed as a one dimensional photonic band-gap crystal by virtue of the periodic spatial perturbation imposed on the fiber core dielectric material. Similar to media supporting Bloch waves, the engraved weak index modulation, presenting a periodic "potential" to an incoming guided mode photon of the fiber, yields useful spectral properties that have been the basis for sensing applications and emerging quantum squeezing and solitons. The response of an FBG sensor to arbitrary external stimuli represents a multiphysics problem without a known analytical solution despite the growing use of FBGs in classical and quantum sensing and metrology. Here, we study this problem by first presenting a solid mechanics model for the thermal and elastic states of a stratified material. The model considers an embedded optical material domain that represents the Bragg grating, here in the form of an FBG. Using the output of this model, we then compute the optical modes and their temperature- and stress-induced behavior. The developed model is applicable to media of arbitrary shape and composition, including soft matter and materials with nonlinear elasticity and geometric nonlinearity. Finally, we employ the computed surface stress and temperature distributions along the grating to analytically calculate the Bragg shift, which is found to be in reasonable agreement with our experimental measurements.