Ali M M, Lim K S, Yang H Z, Chong W Y, Lim W S, Ahmad H
Photonics Research Centre, Department of Physics, Faculty of Science, University of Malaya, Kuala Lumpur, Malaysia.
Appl Opt. 2013 Aug 1;52(22):5393-7. doi: 10.1364/AO.52.005393.
This paper proposes an approach based on an optical imaging technique for the period measurement of fiber Bragg gratings (FBG). The simple, direct technique involves a differential interface contrast (DIC) microscope and a high-resolution CCD camera. Image processing is performed on the microscope images to obtain low-noise grating profiles and then the grating periods. Adopting a large image sample size in the image processing can reduce uncertainty. During the investigation, FBGs of different grating periods are fabricated by prestraining the photosensitive fibers during the UV-writing process. A good linearity between the measured Bragg wavelengths and grating periods is observed and the measured strain-optics coefficient was found to be in agreement with reported literature.
本文提出了一种基于光学成像技术的光纤布拉格光栅（FBG）周期测量方法。这种简单、直接的技术涉及微分干涉衬度（DIC）显微镜和高分辨率电荷耦合器件（CCD）相机。对显微镜图像进行图像处理以获得低噪声的光栅轮廓，进而得到光栅周期。在图像处理中采用大图像样本量可以降低不确定性。在研究过程中，通过在紫外写入过程中对光敏光纤进行预应变来制作不同光栅周期的FBG。观察到测量的布拉格波长与光栅周期之间具有良好的线性关系，并且测量的应变光学系数与已发表文献一致。
