Optical Measurement Method of Electromechanical Effect Based on Fabry-Perot Interference Mechanism

The detection of electromechanical effect plays a vital role in the accurate calibration of wearable devices, microrobots, and nano-electromechanical systems. A high-precision microstrain detection system based on fiber Fabry-Perot (F-P) interference for obtaining precise electromechanical coupling coefficient was established in this article. In light of the structural characteristics of the F-P interferometer, piezoelectric (PZT) was selected as core material embedded in the sensor for forming an optical fiber F-P cavity. The deformation of the sample was detected from the wave shift in the interference spectrum by the system under step voltages. As demonstrated by the results, the fitting degree is obtained between the deformation of the sample and electric field strengths as high as that the coefficient of determination (R2) is 99.97%. The measured resolution could reach to the level of 10 pm in the meantime.