Jia Jingshan, Jiang Yi, Huang Junbin, Hu Jie, Jiang Lan
Opt Express. 2020 Mar 30;28(7):9149-9157. doi: 10.1364/OE.389501.
A symmetrical demodulation method is developed for the recovery of dynamic signals. Extrinsic Fabry-Perot interferometers (EFPIs) with different cavity lengths can be interrogated by a same demodulator. In the demodulation technique, three interferometric signals are introduced by selecting three specified laser wavelength, two of the three signals are symmetrical about the third signal. The dynamic signal is recovered by the proposed method from the three interferometric signals. EFPI sensors in a wide cavity length range (>1000 µm) can be demodulated without dead zone. The calculated amplitude error of the demodulated signal is less than 0.25% with the cavity length in the 20-1005 µm range. The proposed demodulation technique is adapted to the measurement of EFPIs with unsteady cavity lengths and unknown cavity lengths.
为恢复动态信号，开发了一种对称解调方法。不同腔长的外腔法布里-珀罗干涉仪（EFPI）可由同一解调器进行询问。在解调技术中，通过选择三个特定的激光波长引入三个干涉信号，其中两个信号关于第三个信号对称。利用该方法从三个干涉信号中恢复动态信号。宽腔长范围（>1000 µm）内的EFPI传感器可无死区解调。当腔长在20 - 1005 µm范围内时，解调信号的计算幅度误差小于0.25%。所提出的解调技术适用于测量腔长不稳定和未知的EFPI。
