Optical holography in ultrasonics research

Abstract

The paper describes the application of holography methods in ultrasonic vibrations and fields research. The simplest and most easily is applied a classical two expositions holographic interferometric method, by which it may be possible to visualize the vibrations distribution of vibrations systems. According to the registered vibrations distribution of the piezoelectric transducer surface it is possible to calculate by the computer its directional characteristic, and to perform the simulation of acoustic field. For the dynamic registration of a changing ultrasonic vibrations surface distribution it is rather convenient a method of speckled structures, by which there was successfully investigated bimorphic piezoelectric transducers modes. By pulse holography methods there has been registered a volumetric image of single ultrasonic pulses in space. For this investigations and reconstruction of high frequency (in MHz range) ultrasonic fields there is particularly useful a liquid surface holographing method by pulse laser. This method allows to calculating the energetic characteristics of ultrasonic fields - acoustic radiation pressure, ultrasonic intensity, and the directional characteristic of the piezoelectric transducer. The described methods are illustrated by a great number of experimental ultrasonic holograms.