Demodulation method combining virtual reference interferometry and minimum mean square error for fiber-optic Fabry-Perot sensors

• 来源期刊: 中国光学快报（英文版）
• 年，卷（期）: 2018,（1）
• 页码范围: 30-33
• 页数: 4页
• 语种: 英文
• DOI: 10.3788/COL201816.010606

摘要

We propose a cavity length demodulation method that combines virtual reference interferometry (VRI) and minimum mean square error (MMSE) algorithm for fiber-optic Fabry-Perot (F-P) sensors.In contrast to the conventional demodulating method that uses fast Fourier transform (FFT) for cavity length estimation,our method employs the VRI technique to obtain a raw cavity length,which is further refined by the MMSE algorithm.As an experimental demonstration,a fiber-optic F-P sensor based on a sapphire wafer is fabricated for temperature sensing.The VRI-MMSE method is employed to interrogate cavity lengths of the sensor under different temperatures ranging from 28℃ to 1000℃.It eliminates the "mode jumping" problem in the FFT-MMSE method and obtains a precision of 4.8 nm,corresponding to a temperature resolution of 2.0℃ over a range of 1000℃.The experimental results reveal that the proposed method provides a promising,high precision alternative for demodulating fiber-optic F-P sensors.