Experimental investigation of cross-coupling and its influence on the elementary radiation pattern in 1D ultrasound arrays

Cross-coupling mechanisms in ultrasound arrays have deep influences on their performances. Here, to investigate them, the surface displacement of a 1D linear array is measured in water with a laser interferometer. Displacement data are then analyzed in both Time-Space and in Time frequency-Spatial frequency domains. Radiation pattern is then simulated from this data and compared to the radiation pattern of a plane piston and to hydrophone measurements. Cross-coupling influence on the 1D array element behavior is finally compared and discussed. Laser interferometry is shown to be a useful tool for ultrasound array optimization as it allows the identification of vibration modes, the determination of the elementary effective aperture and the radiation pattern of elements.