Fraunhofer Diffraction Pattern Deflected by Highly Absorbed Ultrasound

Abstract

Intensity distribution has been calculated in the Fraunhofer diffraction pattern of the deflected light. The aspect of the variation in the pattern has been obtained for various values of a parameter; a product of the ultrasonic absorption coefficient and one half of the incident beam aperture. The limit of resolution of adjacent spots has been also calculated in accordance with a few definitions concerning the minimum resolvable distance. The calculations have been ascertained by the intensity measurements of the deflected pattern for several kinds of liquids with various absorption coefficients.