Paul Langevin’s contributions to the development of underwater acoustics

Paul Langevin made significant contributions to the understanding of piezoelectricity and the development of piezoceramics materials. For instance, Professor Langevin's invented the quartz sandwich transducer in 1917 for underwater sound transmission. He subsequently used this to develop the first underwater Sonar for submarine detection during World War I, and his work was extensively used the French and American Navy. After world war I, SONAR devices he helped developed were used in several French ocean-liners. We will review Paul Langevin’s most noteworthy contributions to the development of underwater acoustics.