Abstract

In the course of research on synthetic aperture ultrasonic holography, some interesting experiments with artificial holograms were performed. The general idea was to synthesize one dimension of the hologram aperture by frequency control. Thus, a hologram was made by sweeping the frequency of the transducer at each position of a linear scan. When the frequency sweep was linear, the result was much like a Fourier.transform hologram in that linear fringes were obtained. When the frequency was swept quadratically, the familiar Fresnel zone patterns were generated.

© 1986 Optical Society of America