REFRACTO-VIBROMETRY - A CONVENIENT METHOD FOR VISUALIZING ULTRASOUND

A novel method for measuring and visualizing the propagation of the invisible acoustic sound in gases and liquids was developed and tested by the authors [1]. This non-contact method is based on a commercially available scanning laser-Doppler vibrometer. It can be used to measure and visualize ultrasound fields in transparent media. The variation of the optical refractive index n, caused by acoustic waves, is used as measuring effect. This justifies the denomination refracto-vibrometry. This novel method is qualified for investigating and presenting numerous acoustic phenomena. Preliminarily, the paper describes the theoretical fundamentals and the technical equipment of th is method. Capabilities and limits of the refracto-vibrometry are discussed. As instructive examples, the propagation of ultrasound waves in air and water is presented. The animated presentation of the measuring results as videos is very impressive and instructive. In the field of education and in US-transducer design, refracto-vibrometry has a large potential to make acoustics clearer and more feasible for application.