A theoretical model is presented for the study of the near field of light diffracted by ultrasound in an isotropic medium which becomes birefringent in the presence of an acoustic wave. Due to the interference with the sound wave, the diffracted light wave in its near field is seen to act as a quasi-monochromatic light wave which is partially polarized. The degree of coherence ins sen to coincide with the degree of polarization and can be controlled acoustically. Hence coherent laser light can be transformed into incoherent light by sending it through an isotropic material with acoustically induced birefringence. In the experimental part of the work, the non-diagonal elements of the diffracted light beam coherency matrix were measured and a good agreement with the theoretical model was obtained.

Date Published: 11 November 1998
PDF: 10 pages
Proc. SPIE 3581, Acousto-Optics and Applications III, (11 November 1998); doi: 10.1117/12.330468

Published in SPIE Proceedings Vol. 3581:
Acousto-Optics and Applications III
Antoni Sliwinski; Bogumil B. J. Linde; Piotr Kwiek, Editor(s)