Fiber optic ultrasound generator using periodic gold nanopattern fabricated by focused ion beam

Ultrasound generation on optical fiber based on photoacoustic principle is a promising approach for many advanced ultrasonic applications, which require wide bandwidth and compact size in order to achieve high resolution as well as the capability of being operated in limited space. This paper reports a fiber optic photoacoustic ultrasound generator using gold nanopattern. The gold nanopattern with high absorption efficiency was fabricated using focused ion beam (FIB) on the fiber endface, which was excited by a nanosecond laser to generate ultrasound signals via the photoacoustic principle. Experimental results demonstrated that ultrasound signals can be generated by this approach and the fiber optic ultrasound generator can be used in the advanced ultrasonic applications.