Abstract
We developed a planate acoustic lens with a phononic crystal structure for acoustic imaging technology in ocean. To determine the properties of the planate acoustic lens, we simulated the sound field converged by the lens using a finite difference time domain (FDTD) method. In addition, we manufactured a prototype of the planate acoustic lens using stainless-steel rods. In this study, we performed a small-scale trial to reduce the scale to one-tenth the original size of the lens. We measured the sound field converged by the manufactured prototype lens in a water tank. A burst pulse with a frequency of 740 kHz radiated from a transducer. Measurement results agree well with analysis results. The focal distances of measurement and analysis were 12.5 and 11.7 mm, respectively. The measured -3 dB beam width at 3.1 mm almost agrees with the analysis result at 2.3 mm.