Abstract
In order to meet the requirements of having a small structure, a wide frequency band, and high sensitivity for acoustic signal measurement, an acoustic sensor based on a silicon-based grooved microring resonator is proposed. In this paper, the effective refractive index method and the finite element method are used to analyze the optical characteristics of a grooved microring resonator, and the size of the sensor is optimized. The theoretical analysis results show that, when the bending radius reaches 10 μm, the theoretical quality factor is about 106, the sensitivity is 3.14 mV/Pa, and the 3 dB bandwidth is 430 MHz, which is three orders of magnitude larger based on the sensitivity of the silicon-based cascaded resonator acoustic sensor. The sensor exhibits high sensitivity and can be used in hydrophones. The small size of the sensor also shows its potential application in the field of array integration.
Highlights
Acoustic measurement is an important research means in non-destructive testing, underwater anti-submarine monitoring, health observation and biomedical imaging [1,2,3,4]
Traditional optical acoustic sensors based on fiber Fabry–Perot interferometer (FPI) [5,6], polymer fiber [7], or fiber Bragg grating (FBG) [8] have the advantages of high sensitivity and anti-electromagnetic interference compared with piezoelectric hydrophones, playing an important role in acoustic monitoring
The acoustic signal testing technology based on optical microcavity, by virtue of excellent photoacoustic coupling characteristics, can avoid the limitation of selfresonance and narrow frequency and can expand the frequency range by 2–3 orders of magnitude and the sound wave detection frequency to MHz so that the scope of application can be greatly expanded and so that the device can be integrated into a chip, reaching the sub-centimeter-squared level, while ensuring its detection sensitivity
Summary
Acoustic measurement is an important research means in non-destructive testing, underwater anti-submarine monitoring, health observation and biomedical imaging [1,2,3,4]. Traditional optical acoustic sensors based on fiber Fabry–Perot interferometer (FPI) [5,6], polymer fiber [7], or fiber Bragg grating (FBG) [8] have the advantages of high sensitivity and anti-electromagnetic interference compared with piezoelectric hydrophones, playing an important role in acoustic monitoring. Most of these optical hydrophones rely on the amount of mechanical deformation to realize acoustic signal sensing and cannot avoid the limitations of self-resonance and narrow frequency. Through theoretical analysis and simulation analysis, the photoacoustic coupling mechanism and acoustic sensing characteristics of the resonator are discussed, and the results show that it has good performance in acoustic sensing
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