Fu X, Lu P, Zhang L, Ni W J, Liu D M, Zhang J S
Opt Express. 2018 Aug 20;26(17):22064-22074. doi: 10.1364/OE.26.022064.
In this work, we investigate the Fourier characteristics of wavelength-scanned optical spectrum of low-finesse Fabry-Pérot (FP) acoustic sensor both theoretically and experimentally. The wavelength scanning will transform the time-domain acoustic signal into phase modulation loaded on the FP sensor spectrum distributed along wavelength. Therefore the interference spectrum can be regarded as carrier signal in the wavelength domain. From this perspective, it is intelligible that the phase modulation loaded on the spectrum (carrier signal) will introduce sidebands in Fourier domain. The spatial frequency and phase of sideband components contain unique information of both acoustic signal and the corresponding sensor. These conclusions are experimentally proved by single sensor head as well as two parallel sensors. The Fourier characteristics of sideband components can be utilized to recognize and distinguish acoustic signals received by different sensors, indicating that it has potential applications in multiplexed FP sensor array and source localization, and so forth.
在这项工作中，我们从理论和实验两方面研究了低精细度法布里 - 珀罗（FP）声学传感器波长扫描光谱的傅里叶特性。波长扫描会将时域声学信号转换为加载在沿波长分布的FP传感器光谱上的相位调制。因此，干涉光谱可被视为波长域中的载波信号。从这个角度来看，加载在光谱（载波信号）上的相位调制会在傅里叶域中引入边带，这是可以理解的。边带分量的空间频率和相位包含声学信号以及相应传感器的独特信息。这些结论通过单传感器头以及两个平行传感器得到了实验验证。边带分量的傅里叶特性可用于识别和区分不同传感器接收到的声学信号，这表明它在复用FP传感器阵列和源定位等方面具有潜在应用。
