2019_programme: AN AUTOMATED MEASUREMENT SYSTEM FOR PHASE SHIFT SENSITIVITY OF INTERFEROMETRIC FIBER OPTIC HYDROPHONE USING BESSEL FUNCTION RATIO METHOD

• Session: 02. Underwater acoustic calibration, testing, facilities and standards
  Organiser(s): Robinson Stephen, Humphrey Victor, Linné Markus, Évora Victor
• Lecture: AN AUTOMATED MEASUREMENT SYSTEM FOR PHASE SHIFT SENSITIVITY OF INTERFEROMETRIC FIBER OPTIC HYDROPHONE USING BESSEL FUNCTION RATIO METHOD
  Paper ID: 832
  Author(s): Zhang Jun, Chen Yi, Zhao Han, Yang Liuqing
  Presenter: Zhang Jun
  Presentation type: oral
  Abstract: Phase shift sensitivity of interferometric fiber optic hydrophone is one of its main performance indicators. In this paper, an automatic measurement system for phase shift sensitivity of interferometric fiber optic hydrophone based on Bessel function ratio method is introduced in detail. In a given frequency acoustic field, the interference optical signal of an interferometric fiber-optic hydrophone is expanded by Bessel series. The ratio of the third-harmonic component to the fundamental component or the ratio of the fourth-harmonic component to the second-harmonic component has a specific relationship with the phase shift of the interferometric fiber-optic hydrophone caused by sound pressure. Because of the curve distribution characteristics of Bessel virtual number and ratio, when the acoustic signal is too large, the phase shift of interferometric light corresponding to the ratio has multi-value. The automatic measurement algorithm can monitor, judge and control the emitted acoustic wave in real time, so that the ratio is always in the first monotone change range of Bessel virtual volume and ratio curve, and can judge the ratio of the third-harmonic component to the fundamental frequency component and the ratio of the fourth-harmonic component to the second-harmonic component, and automatically select the result with higher signal-to-noise ratio. The experimental results show that the system can effectively measure the phase shift sensitivity of the interferometric fiber optic hydrophone automatically by using the Bessel function ratio method. The system is simple in structure, high in efficiency and reliable in data.
• Corresponding author: Mr Zhang Jun
  Affiliation: Hangzhou Applied Acoustics Research Institute
  Country: China
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