Ultrasound-to-plastic optical fiber coupling as an acoustic source probe

An integrated ultrasonic detection system that consists of emission and detection has been proposed and demonstrated experimentally. The proposed emission source is based on plastic optical fiber (POF). In order to promote the coupling of ultrasound-to-POF, and the end of the POF is heated to form a circular pedestal. A homemade fiber Fabry–Perot interferometer is employed to evaluate the coupling efficiency of ultrasound-to-POF. The sensing head is spliced with a short section of hollow-core fiber and single-mode fiber, resulting in an air microbubble formation by discharging. The experimental results show that ultrasound can be transmitted effectively in a narrow space using the coupling method, and the compact sensor also presents a considered sensitivity for ultrasonic detection. This all-fiber ultrasonic interrogation can be integrated as a system for the application in the bioimaging field, especially the organism body.