METHOD OF ADJUSTING MAXIMUM SENSITIVITY OF FIBRE-OPTIC HYDROPHONE Russian patent published in 2017 - IPC H04R29/00 

FIELD: physics, measurement technology.

SUBSTANCE: invention relates to metrology, particularly to methods of calibrating hydrophones. The method of adjusting maximum sensitivity of a fibre-optic hydrophone comprises transmitting light via a fibre-optic line to a micro-membrane, with subsequent reception of reflected light with a photodetector. Method comprises using amplitude- and frequency-modulated light, using modulated laser radiation to generate a signal with modulation frequency close to the resonance frequency of the micro-membrane, which is used to excite forced vibrations of the micro-membrane; measuring resonance frequency of the micro-membrane ν, then at constant power, measuring wavelength of radiation from the light source in a range exceeding spectral width of free dispersion of a Fabry-Perot interferometer, according to a mathematical expression which takes into account distance from the reflecting surface of the micro-membrane too the end surface of a single-mode fibre-optic guide H₀, and the refraction index of the medium n. The method then includes measuring extreme values of radiation wavelength λ_max and λ_min, corresponding to output signals, calculating the average value, changing the radiation wavelength to a value λ_k, corresponding to the average value U_sr of the output signal.

EFFECT: invention increases hydrophone sensitivity.

2 cl, 2 dwg