Optical measurement of sound fields information using Mach-Zehnder interferometer

An optical method for measuring information of sound fields using the Mach- Zehnder interferometer is described. The Mach-Zehnder interferometer is adv antageous for obtaining quantitative measurements of phase values in compar ison to other visualization methods. In this study, we simultaneously inves tigate a two-dimensional data acquisition system for the projection image o f an optical phase deviation in proportion to sound fields below the freque ncy of 2.16 MHz. In the experiment, the charge-coupled device (CCD) camera is used as a function of a mean value detector. The experimental results of the optical phase deviation along the ultrasound axis are useful as primar y data for estimating the sound pressure. The two-dimensional measurement s ystem using a CCD camera proposed in this paper has the advantages of acqui ring the data in a short time when used in an environment where the measure ment conditions change.