Impluse response of a fiber optic probe hydrophone determined with shock waves in water

The impluse response of a fiber optic probe hydrophone (FOPH) is determined through it’s step response obtained by using a self-focusing electromagnetic shock wave excitation. The experimental transfer function agrees well with the theoretical calculation of the transient response by diffraction of the acoustic wave at the fiber end face. A rise time of about 5 ns has been obtained for the shock front of the self-focusing shock wave generator by the deconvolution of the output signal of the hydrophone with it’s impulse response. The FOPH can be used as a standard hydrophone for the absolute wideband measurement of shock waves of lithotripters and of acoustic waves in liquids in general.