Abdi Abdeq M, Suzuki Shigeru, Schülzgen Axel, Kost Alan R
Saada Optical, LLC, Saint Louis, Missouri 63110, USA.
Appl Opt. 2007 May 10;46(14):2563-74. doi: 10.1364/ao.46.002563.
The modeling, design, simulation, fabrication, calibration, and testing of a three-element, 15.3 cm fiber Bragg grating strain sensor array with the coherent optical frequency domain reflectometry (C-OFDR) interrogation technique are demonstrated. The fiber Bragg grating array (FBGA) is initially simulated using in-house software that incorporates transfer matrices. Compared to the previous techniques used, the transfer matrix method allows a systemwide approach to modeling the FBGA-C-OFDR system. Once designed and simulated, the FBGA system design is then imprinted into the core of a boron-germanium codoped photosensitive fiber using the phase mask technique. A fiber optic Fabry-Perot interferometric (FPI) strain gauge calibrator is then used to determine the strain gauge factor of a single fiber Bragg grating (FBG), and the results are used on the FBGA. The FPI strain gauge calibrator offers nondestructive testing of the FBG. To test the system, the FBGA is then attached to a 75 cm cantilever beam and interrogated using an incremental tunable laser. Electric strain gauges (ESGs) are then used to independently verify the strain measurements with the FBGA at various displacements of the cantilever beam. The results show that the peak strain error is 18% with respect to ESG results. In addition, good agreement is shown between the simulation and the experimental results.
本文展示了采用相干光频域反射法（C - OFDR）询问技术的三元件、15.3厘米光纤布拉格光栅应变传感器阵列的建模、设计、仿真、制造、校准和测试。光纤布拉格光栅阵列（FBGA）最初使用包含传输矩阵的内部软件进行模拟。与之前使用的技术相比，传输矩阵法允许采用系统范围的方法对FBGA - C - OFDR系统进行建模。一旦设计和模拟完成，FBGA系统设计随后使用相位掩膜技术刻写在硼锗共掺杂光敏光纤的纤芯中。然后使用光纤法布里 - 珀罗干涉（FPI）应变仪校准器来确定单根光纤布拉格光栅（FBG）的应变系数，并将结果应用于FBGA。FPI应变仪校准器提供对FBG的无损测试。为了测试该系统，将FBGA附着到一根75厘米的悬臂梁上，并使用增量可调激光器进行询问。然后使用电应变仪（ESG）在悬臂梁的不同位移下独立验证FBGA的应变测量结果。结果表明，相对于ESG结果，峰值应变误差为18%。此外，仿真结果与实验结果显示出良好的一致性。
