Accession Number : AD0775288

Title :   Methods for Acoustic Holography and Acoustic Measurements.

Descriptive Note : Technical rept.,

Corporate Author : NAVAL UNDERWATER SYSTEMS CENTER NEW LONDON CONN NEW LONDON LAB

Personal Author(s) : Fischer,Wolfgang K.

Report Date : 27 DEC 1973

Pagination or Media Count : 250

Abstract : A novel 'four step acoustical holographic imaging system' is described and several means to implement it are theoretically and experimentally analyzed. The 'holographic sound image converter,' consisting of an optical 'holographic interferometer' and an acoustic 'coupler' is introduced, analyzed, and compared to existing acoustic detectors and a number of its advantages are cited. The new technique of 'shifted reference holographic interferometry' is presented. Also, a detailed study is conducted concerning the development and testing of a mechanical velocity transformer consisting of two lossy, nearly quarter-wave plates. (Modified author abstract)

Descriptors :   *Holography, Acoustic waves, Acoustic detectors, Image converters, Interferometry, Ultrasonic radiation

Subject Categories : Holography
      Acoustics

Distribution Statement : APPROVED FOR PUBLIC RELEASE