Liao Hao, Lu Ping, Fu Xin, Jiang Xinyue, Ni Wenjun, Liu Deming, Zhang Jiangshan
Opt Express. 2017 Oct 30;25(22):26898-26909. doi: 10.1364/OE.25.026898.
In this paper, a novel sensitivity amplification method for fiber-optic in-line Mach-Zehnder interferometer (MZI) sensors has been proposed and demonstrated. The sensitivity magnification is achieved through a modified Vernier-effect. Two cascaded in-line MZIs based on offset splicing of single mode fiber (SMF) have been used to verify the effect of sensitivity amplification. Vernier-effect is generated due to the small free spectral range (FSR) difference between the cascaded in-line MZIs. Frequency component corresponding to the envelope of the superimposed spectrum is extracted to take Inverse Fast Fourier Transform (IFFT). Thus we can obtain the envelope precisely from the messy superimposed spectrum. Experimental results show that a maximum sensitivity amplification factor of nearly 9 is realized. The proposed sensitivity amplification method is universal for the vast majority of in-line MZIs.
本文提出并演示了一种用于光纤在线马赫-曾德尔干涉仪（MZI）传感器的新型灵敏度放大方法。灵敏度放大是通过改进的游标效应实现的。基于单模光纤（SMF）错位熔接的两个级联在线MZI被用于验证灵敏度放大的效果。由于级联在线MZI之间的自由光谱范围（FSR）差异较小，产生了游标效应。提取与叠加光谱包络对应的频率分量进行快速傅里叶逆变换（IFFT）。这样我们就可以从杂乱的叠加光谱中精确地获得包络。实验结果表明，实现了近9的最大灵敏度放大倍数。所提出的灵敏度放大方法对绝大多数在线MZI具有通用性。
