Broadband Acoustic Vibration Sensor Based on Cladding-Mode Resonance of Double-Cladding Fiber

• 来源期刊: 光子传感器（英文版）
• 关键词: Double-cladding fiber acoustic vibration sensor coaxial coupler
• 年，卷（期）: 2019,（3）
• 页码范围: 230-238
• 页数: 9页
• 语种: 英文
• DOI: 10.1007/s13320-019-0548-7

摘要

We have proposed and demonstrated a double-cladding fiber (DCF) with cladding-mode resonance property for broadband acoustic vibration sensing.Since the fundamental mode in the core waveguide is able to be coupled to LP05 mode in the tube waveguide once the phase-matching condition is fulfilled,the transmission spectrum can exhibit a dip with a large extinction ratio.An acoustic vibration could induce the wavelength shift of such transmission spectrum,so that the intensity variation at a wavelength near the dip is coded with the information of the acoustic vibration signal.By demodulating the response of intensity variation,the frequency of the applied acoustic vibration signal can be recovered.Such a DCF-based sensor with an intensity modulation could measure the acoustic vibration with a broadband frequency range from 1 Hz to 400kHz and exhibits the maximum signal-to-noise ratio (SNR) of～80.79 dB when the vibration frequency is 20 kHz.The obtained results show that the proposed DCF-based acoustic vibration sensor has a potential application in environmental assessment,structural damage detection,and health monitoring.