Initial Nonreciprocal Phase Shift Measurement Method for Reflective Fiber Optical Voltage Sensor

The reflective piezoelectric effect fiber optic voltage sensor (RFOVS) encounters significant challenges in practical application. Due to limitations in the manufacturing process, achieving the theoretically reciprocal structure for RFOVS proves challenging. This limitation significantly impacts measurement accuracy due to the initial nonreciprocal phase shift and environmental-induced phase shift. This study introduces a novel measurement approach to address this challenge, facilitating a straightforward and efficient assessment of the initial nonreciprocal phase shift. This is achieved by precisely measuring the wavelength and wavelength spacing at adjacent troughs of intensity within the spectrum. Simulation analysis and experimental results demonstrate the efficacy of this measurement method, reducing the nonreciprocal phase shift error of the RFOVS to just 1/45 of its initial value. This discovery provides practical solutions and theoretical foundations for addressing the initial nonreciprocal phase shift issue in RFOVS, thereby promoting its practical application.