Fresnel plate consists of radially symmetric zones. Zones alternate between opaque and transparent, and are spaced so that wave transmitted by the transparent zones constructively interferes at the desired focus. Modeling and experimental results of a flat lens for use in air are presented and the optimized design parameters are used to fabricate the lens. The theoretical calculation for the focal length is determined to be 20.0 cm and the incident wave length of 3500 Hz. The results show a sharp focal spot with very high amplitude.
ACOUSTIC LENS
Fresnel plate consists of radially symmetric zones. Zones alternate between opaque and transparent, and are spaced so that wave transmitted by the transparent zones constructively…