Huang D W, Yang C C
Department of Electrical Engineering and Graduate Institute of Electro-Optical Engineering, National Taiwan University, 1 Roosevelt Road, Section 4, Taipei, Taiwan.
Appl Opt. 1999 Jul 20;38(21):4494-9. doi: 10.1364/ao.38.004494.
Reconstruction of the refractive-index profiles of fiber gratings from their complex Bragg reflection spectra is experimentally demonstrated. The amplitude and phase of the complex reflection spectrum were measured with a balanced Michelson interferometer. By integrating the coupled-mode equations, we built the relationship between the complex coupling coefficient and the complex reflection spectrum as an iterative algorithm for reconstructing the index profile. This method is expected to be useful for reconstructing the index profiles of fiber gratings with any apodization, chirp, or dc structures. An apodized chirped grating and a uniform grating with a depression of index modulation were used to demonstrate the technique.
通过实验证明了从光纤光栅的复布拉格反射光谱重建其折射率分布的方法。使用平衡迈克尔逊干涉仪测量复反射光谱的幅度和相位。通过对耦合模方程进行积分，建立了复耦合系数与复反射光谱之间的关系，作为一种重建折射率分布的迭代算法。该方法有望用于重建具有任何切趾、啁啾或直流结构的光纤光栅的折射率分布。使用一个切趾啁啾光栅和一个折射率调制有凹陷的均匀光栅来演示该技术。
