(Peer-Reviewed) Highly sensitive and miniature microfiber-based ultrasound sensor for photoacoustic tomography
Liuyang Yang 杨留洋 ¹, Yanpeng Li 李岩鹏 ¹, Fang Fang 方芳 ¹, Liangye Li 李良晔 ¹, Zhijun Yan 闫志君 ¹, Lin Zhang 张琳 ², Qizhen Sun 孙琪真 ¹
¹ School of Optical and Electronic Information & National Engineering Laboratory for Next Generation Internet Access System (NGIA) & Wuhan National Laboratory for Optoelectronics (WNLO), Huazhong University of Science and Technology, Wuhan 430074, China
中国 武汉 华中科技大学光学与电子信息学院 下一代互联网接入系统国家工程研究中心 武汉光电国家实验室
² Aston Institute of Photonic Technologies, Aston University, Birmingham B4 7ET, UK
A microfiber with large evanescent field encapsulated in PDMS is proposed and demonstrated for ultrasound sensing. The compact size and large evanescent field of microfiber provide an excellent platform for the interaction between optical signal and ultrasound wave, exhibiting a high sensitivity of 3.5 mV/kPa, which is approximately 10 times higher than the single-mode fiber sensor. Meanwhile, a phase feedback stabilization module is introduced into the coherent demodulation system for long-term stable measurement.
In addition, a photoacoustic tomography experiment with the microfiber ultrasound sensor is implemented to verify the excellent performance on imaging, with the depth of 12 mm, the highest lateral resolution of 65 μm and axial resolution of 250 μm, respectively. The highly sensitive microfiber ultrasound sensor provides a competitive alternative for various applications, such as industrial non-destructive testing, biomedical ultrasound and photoacoustic imaging.