Accession Number : ADA307951

Title :   The Focusing Properties of an Acoustic Thin Lens and Zone Plate.

Descriptive Note : Technical rept.,

Corporate Author : PENNSYLVANIA STATE UNIV UNIVERSITY PARK APPLIED RESEARCH LAB

Personal Author(s) : Hughes, W. J. ; Craig, J. R.

PDF Url : ADA307951

Report Date : APR 1996

Pagination or Media Count : 37

Abstract : A thin lens is defined as one that has thickness very small compared to the object or image distances. There are several parameters, or degrees of freedom, that must be determined when designing a lens for a specific application. The radii of curvature of the surfaces, the types of materials to use and their indices of refraction, the diameter, the thickness desired, and the focal length that can be tolerated are all parameters that may be varied to obtain the desired lens performance. An additional requirement for this application is size and weight. It is always desirable to be as lightweight and as small as possible. The complete design must be as close to neutrally buoyant as possible. This puts some limitations on the materials that can be used.

Descriptors :   *UNDERWATER ACOUSTICS, *ACOUSTIC LENSES, REFRACTIVE INDEX, DEGREES OF FREEDOM, LIMITATIONS, FOCUSING, THINNESS, BUOYANCY, ACOUSTIC REFRACTION.

Subject Categories : Acoustics

Distribution Statement : APPROVED FOR PUBLIC RELEASE