Fiber-optic ultrasound generator using periodic gold nanopores fabricated by a focused ion beam

Ultrasound generation from an optical fiber, based on the photoacoustic principle, is a promising approach to many ultrasonic applications, specifically those requiring wide bandwidth and compact size in order to achieve high resolution as well as the capability of being operated in limited space. A fiber-optic ultrasound generator using gold nanopores is reported. The gold nanopores, having high absorption efficiency, were fabricated using a focused ion beam (FIB) on the fiber endface, which was excited by a nanosecond laser in order to generate ultrasound signals via the photoacoustic principle. Experimental results demonstrate that these wide bandwidth ultrasound signals can be generated by this compact fiber-optic ultrasound generator fabricated using a FIB.