光纤超声传感器的射频域自相干解调技术  

Radio-frequency heterodyne detection of fiber-optic ultrasonic sensor

作　　者：刘付武兴 梁贻智 曹君杰 仲晓轩 李金莹 黄卫[2] 金龙[1] LIUFU Wuxing;LIANG Yizhi;CAO Junjie;ZHONG Xiaoxuan;LI Jinying;HUANG Wei;JIN Long(College of Physics and Optoelectronics Engineering,Guangdong Provincial Key Laboratory on Optical Fiber Sensing and Communications,Jinan University,Guangzhou 510632,China;Department of Gastroenterology,First Affiliated Hospital of Jinan University,Guangzhou 510632,China)

机构地区：[1]暨南大学物理与光电工程学院广东省光纤传感与通信技术重点实验室,广东广州510632 [2]暨南大学附属第一医院消化内科,广东广州510632

出　　处：《光学精密工程》2024年第17期2708-2717,共10页Optics and Precision Engineering

基　　金：国家自然科学基金资助项目(No.62275104,No.62322506,No.62122031,No.62135006);广东省基础与应用基础研究基金资助项目(No.2023A1515220038);广州市重点研发计划项目(No.2060404);广州市-暨南大学市校联合资助项目(No.202201020043)。

摘　　要：在光纤光声成像技术中,检测灵敏度是决定光纤超声传感器成像质量的关键性因素之一。以小型化正交双频光纤激光器为超声敏感元件,建立更好的信号解调技术对声致相位变化进行检测,以实现高灵敏度超声检测和光声成像。引入射频域自相干解调技术对超声波引起的激光频率变化进行读取,实验结果表明,该技术具有超声响应信号放大效果,传感器的灵敏度在8~32 MHz的超声频率内获得了显著提升,将最小可检测声压从9.0 Pa降低到5.7 Pa。进一步地,将该超声检测技术应用于活体光声显微成像,发现在同等光强的激发条件下,图像信噪比获得逾4 dB的提升。该技术为光纤光声成像技术的应用拓展奠定了坚实的技术基础。The detection sensitivity of fiber-optic ultrasound sensors is crucial for image quality in fiberbased photoacoustic imaging.In this study,we employed a dual-polarization fiber laser as the acoustic sensing element and introduced radio-frequency heterodyne demodulation for sensitivity enhancement.Ex⁃perimental results demonstrate that this method effectively eliminates noise from additional local radio-fre⁃quency oscillation sources.The proposed technique achieved an improved sensitivity,evidenced by a noise-equivalent pressure(NEP)of 9.0 Pa,compared to the 5.7 Pa offered by previous approaches with in the frequency range of 8-32 MHz.Furthermore,applying this sensor to photoacoustic microscopy re⁃sulted in a signal-to-noise ratio enhancement of over 4 dB.The heterodyne detection technology signifi⁃cantly improves the sensitivity and image signal-to-noise ratio of fiber-optic sensors,facilitating the applica⁃tion of fiber-based photoacoustic imaging.

关 键 词：光纤光声成像 光纤激光传感器 光纤超声传感器 自相干解调 

分 类 号：TN253[电子电信—物理电子学] TH691.9[机械工程—机械制造及自动化]