An optical fiber hydrophone based on equivalent phase shift fiber Bragg grating （EPS-FBG） with temperature compensation package provides an improvement of sensitivity in underwater acoustic measurement at wide frequ...An optical fiber hydrophone based on equivalent phase shift fiber Bragg grating （EPS-FBG） with temperature compensation package provides an improvement of sensitivity in underwater acoustic measurement at wide frequency range, from 2.SkHz to 12kHz. The acoustic pressure is transduced into elastic vibration of a circle metal disk, resulting in an intensity modulation of the reflected light wave back from fiber Bragg grating （FBG）. Experiment shows that the 500 EPS-FBG hydrophone has a minimum detectable acoustic pressure of about at 5 kHz and achieves about 18-dB improvement of acoustic pressure sensitivity compared with a regular apodized FBG hydrophone.展开更多
A fiber Bragg grating （FBG） hydrophone with enhanced sensitivity is demonstrated. A novel piston-like diaphragm with a hard core fixed at the center is used as the sensing element. Theoretical analysis shows that th...A fiber Bragg grating （FBG） hydrophone with enhanced sensitivity is demonstrated. A novel piston-like diaphragm with a hard core fixed at the center is used as the sensing element. Theoretical analysis shows that the Young＇s modulus of the diaphragm and the radius of the hard core have significant effect on the pressure sensitivity. Experiments are carried out to test this effect and the performance of the hydrophone. The static measure- ment result is in good agreement with the theoretical result and an acoustic sensitivity of 7 nm/MPa has been achieved.展开更多
Fiber laser hydrophones have got widespread concems due to the unique advantages and broad application prospects. In this paper, the research results of the eight-element multiplexed fiber laser acoustic pressure arra...Fiber laser hydrophones have got widespread concems due to the unique advantages and broad application prospects. In this paper, the research results of the eight-element multiplexed fiber laser acoustic pressure array and the interrogation system are introduced, containing low-noise distributed feedback fiber laser （DFB-FL） fabrication, sensitivity enhancement packaging, and interferometric signal demodulation. The frequency response range of the system is 10Hz-10kHz, the laser frequency acoustic pressure sensitivity reaches 115 dB re Hz/Pa, and the equivalent noise acoustic pressure is less than 60μa/Hz^1/2. The dynamic range of the system is greater than 120 dB.展开更多
文摘An optical fiber hydrophone based on equivalent phase shift fiber Bragg grating （EPS-FBG） with temperature compensation package provides an improvement of sensitivity in underwater acoustic measurement at wide frequency range, from 2.SkHz to 12kHz. The acoustic pressure is transduced into elastic vibration of a circle metal disk, resulting in an intensity modulation of the reflected light wave back from fiber Bragg grating （FBG）. Experiment shows that the 500 EPS-FBG hydrophone has a minimum detectable acoustic pressure of about at 5 kHz and achieves about 18-dB improvement of acoustic pressure sensitivity compared with a regular apodized FBG hydrophone.
基金supported by the National 863 Program under Grant No. 2007AA03Z415.
文摘A fiber Bragg grating （FBG） hydrophone with enhanced sensitivity is demonstrated. A novel piston-like diaphragm with a hard core fixed at the center is used as the sensing element. Theoretical analysis shows that the Young＇s modulus of the diaphragm and the radius of the hard core have significant effect on the pressure sensitivity. Experiments are carried out to test this effect and the performance of the hydrophone. The static measure- ment result is in good agreement with the theoretical result and an acoustic sensitivity of 7 nm/MPa has been achieved.
基金Acknowledgment This work was financially supported by the National Natural Science Foundation of China （No. 60317101）, Key Research and Development Plan of Shandong Province （No. 2015GSF11500）, and Natural Science Foundation of Shandong Province （No. ZR2013FL029）.
文摘Fiber laser hydrophones have got widespread concems due to the unique advantages and broad application prospects. In this paper, the research results of the eight-element multiplexed fiber laser acoustic pressure array and the interrogation system are introduced, containing low-noise distributed feedback fiber laser （DFB-FL） fabrication, sensitivity enhancement packaging, and interferometric signal demodulation. The frequency response range of the system is 10Hz-10kHz, the laser frequency acoustic pressure sensitivity reaches 115 dB re Hz/Pa, and the equivalent noise acoustic pressure is less than 60μa/Hz^1/2. The dynamic range of the system is greater than 120 dB.
