Guangdong Provincial Key Laboratory of Optical Fiber Sensing and Communications, Institute of Photonics Technology, Jinan University, Guangzhou 510632, China.
Department of Mechanical and Biomedical Engineering, City University of Hong Kong, 83 Tat Chee Ave, Kowloon, Hong Kong SAR, China.
Sci Rep. 2017 Jan 18;7:40849. doi: 10.1038/srep40849.
Photoacoustic imaging, especially for intravascular and endoscopic applications, requires ultrasound probes with miniature size and high sensitivity. In this paper, we present a new photoacoustic sensor based on a small-sized fiber laser. Incident ultrasound waves exert pressures on the optical fiber laser and induce harmonic vibrations of the fiber, which is detected by the frequency shift of the beating signal between the two orthogonal polarization modes in the fiber laser. This ultrasound sensor presents a noise-equivalent pressure of 40 Pa over a 50-MHz bandwidth. We demonstrate this new ultrasound sensor on an optical-resolution photoacoustic microscope. The axial and lateral resolutions are 48 μm and 3.3 μm. The field of view is up to 1.57 mm. The sensor exhibits strong resistance to environmental perturbations, such as temperature changes, due to common-mode cancellation between the two orthogonal modes. The present fiber laser ultrasound sensor offers a new tool for all-optical photoacoustic imaging.
光声成像是一种医学成像技术，尤其适用于血管内和内窥镜应用，需要使用具有微型尺寸和高灵敏度的超声探头。在本文中，我们提出了一种基于小型光纤激光器的新型光声传感器。入射超声波对光纤激光器施加压力，引起光纤的谐波振动，通过光纤激光器中两个正交偏振模式之间的拍频信号的频移来检测该振动。该超声传感器在 50MHz 的带宽内呈现出 40Pa 的等效噪声压力。我们在光学分辨率光声显微镜上演示了这种新型超声传感器。轴向和侧向分辨率分别为 48μm 和 3.3μm。视场可达 1.57mm。由于两个正交模式之间的共模消除，该传感器对环境干扰（如温度变化）具有很强的抗干扰能力。这种新型光纤激光超声传感器为全光学光声成像提供了一种新工具。
