Wideband focused film transducer for optoacoustic tomography

Abstract

The response of a focused film transducer to wideband acoustic signals is studied both theoretically and experimentally. The transducer has the form of a narrow PVDF strip placed on a concave cylindrical surface. A software package is developed for calculating the impulse transient response functions depending on the position of the point source of spherical waves. The experiments are performed using laser thermooptical sources of acoustic spherical wave pulses excited by a pulsed diode-pumped Nd: YAG laser. The theoretical and measured temporal profiles of signals recorded by the transducer are shown to be in good agreement for the source positioned near the transducer’s focus. For this region, a transducer sensitivity map is investigated. For the case of the source positioned at the focus of the transducer, the absolute value of the transducer sensitivity is 8 µV/Pa.