Based on the piezo-optic effect of medium, the refractive index of medium is the function of its density, and so it's also the function of acoustic pressure. Therefore, acoustic pressure in the optical path everyw...Based on the piezo-optic effect of medium, the refractive index of medium is the function of its density, and so it's also the function of acoustic pressure. Therefore, acoustic pressure in the optical path everywhere can be determined absolutely by laser-interferometric technique and relative distribution of pressure in the middle and far acoustic field, which can be obtained from theory or experiment respectively. Theory and experiment of measurement of pressure in acoustic field with laser-interferometer are introduced. Distribution of pressure radiated by a power ultrasonic transducer is determined by laser interferometric technique. The theoretical and experimental results are in good agreement. The receiving sensitivity of a PVDF (Polyvinylidene fluoride) transducer in free field is also calibrated absolutely due to above results and its sensitivity is -118.5 dB.展开更多
A novel distributed feedback（DFB） fiber laser sensor, which can measure acoustic and magnetic fields simultaneously, is proposed. The magnetic field can be measured by detecting the change of resonant frequency of t...A novel distributed feedback（DFB） fiber laser sensor, which can measure acoustic and magnetic fields simultaneously, is proposed. The magnetic field can be measured by detecting the change of resonant frequency of the fiber laser, and the acoustic pressure can be measured by detecting the phase shift of the fiber laser. Both of the signals can be simultaneously demodulated in the frequency domain without affecting each other. Experimental studies show that the acoustic pressure sensitivity of this sensor is about-130 d B（0 dB re 1 pm∕μPa） and the sensor has a good linearity with a magnetic field sensitivity of 0.57 Hz∕mT.展开更多
基金National Natural Science Foundation of China!(No.59738150)
文摘Based on the piezo-optic effect of medium, the refractive index of medium is the function of its density, and so it's also the function of acoustic pressure. Therefore, acoustic pressure in the optical path everywhere can be determined absolutely by laser-interferometric technique and relative distribution of pressure in the middle and far acoustic field, which can be obtained from theory or experiment respectively. Theory and experiment of measurement of pressure in acoustic field with laser-interferometer are introduced. Distribution of pressure radiated by a power ultrasonic transducer is determined by laser interferometric technique. The theoretical and experimental results are in good agreement. The receiving sensitivity of a PVDF (Polyvinylidene fluoride) transducer in free field is also calibrated absolutely due to above results and its sensitivity is -118.5 dB.
基金supported by the Key R&D Program of China(No.2017YFB0405503)the Youth Innovation Promotion Association of CAS(No.2016106)
文摘A novel distributed feedback（DFB） fiber laser sensor, which can measure acoustic and magnetic fields simultaneously, is proposed. The magnetic field can be measured by detecting the change of resonant frequency of the fiber laser, and the acoustic pressure can be measured by detecting the phase shift of the fiber laser. Both of the signals can be simultaneously demodulated in the frequency domain without affecting each other. Experimental studies show that the acoustic pressure sensitivity of this sensor is about-130 d B（0 dB re 1 pm∕μPa） and the sensor has a good linearity with a magnetic field sensitivity of 0.57 Hz∕mT.
