Liang Yizhi, Liu Jin-Wei, Jin Long, Guan Bai-Ou, Wang Lidai
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.
Biomed Opt Express. 2018 Oct 29;9(11):5809-5816. doi: 10.1364/BOE.9.005809. eCollection 2018 Nov 1.
Optical-resolution photoacoustic microscopy (OR-PAM) images biological tissue with sub-cellular resolution and optical absorption contrast. OR-PAM is limited by the tradeoff among imaging speed, field of view, and sensitivity. In this work, we present an OR-PAM technique based on an unfocused side-looking fiber optic ultrasound (FOUS) sensor, which achieves high imaging speed, large field of view, and good sensitivity for imaging. The FOUS sensor is developed based on a dual-polarized fiber laser and read out with real-time frequency demodulation. Via minimizing the readout noise, the sensor offers a noise-equivalent pressure of 43.6 Pa, enabling high detection sensitivity over a large field of view. High imaging speed is achieved via scanning the laser beam with a 2D galvo mirror in the ultrasound detection area. Microvascular imaging with a frame rate of 2 Hz over a 2 × 2 mm area has been demonstrated in the mouse ear. The new OR-PAM technique may be used in the visualization of biological and physiologic dynamics.
光学分辨率光声显微镜（OR-PAM）能够以亚细胞分辨率和光吸收对比度对生物组织进行成像。OR-PAM受到成像速度、视野和灵敏度之间权衡的限制。在这项工作中，我们提出了一种基于非聚焦侧视光纤超声（FOUS）传感器的OR-PAM技术，该技术在成像时实现了高成像速度、大视野和良好的灵敏度。FOUS传感器基于双偏振光纤激光器开发，并通过实时频率解调进行读出。通过最小化读出噪声，该传感器提供了43.6 Pa的等效噪声压力，从而在大视野范围内实现了高检测灵敏度。通过在超声检测区域用二维振镜扫描激光束实现了高成像速度。在小鼠耳部已证明在2×2 mm区域内以2 Hz的帧率进行微血管成像。这种新的OR-PAM技术可用于生物和生理动态的可视化。
