Fiber optic photoacoustic device: high efficiency and wide bandwidth ultrasonic source

General purpose fiber optic photacoustic source is proposed. The working principle is based on thermal conversion of laser pulses into a metallic film evaporated directly onto the tip of an fiber optic. It will be demonstrated both theoretically and experimentally, that metallization improves the spectral characteristics of the produced ultrasound with respect to direct irradiation of a liquid or biological tissue. In effect the proposed source exhibits a flat band, nearly ideal, at high frequencies. In addition, it will be shown that the metallization considerably improves photoacoustic conversion efficiency.