Abstract
Optical systems have the properties that a relation of Fourier transform exists between the light wave amplitude distributions at the front and back focal planes of a lens of the system and that at the same time multiplication is performed by a simple imaging process, namely by making the first transparency imaged on the second. This paper presents the method of realization, the operational principles and theoretical considerations of the optical correlator which consists of two ultrasonic light modulators and three lenses, taking advantage of the light diffraction by traveling ultrasonic waves and the optical properties described above. Some experimental results are also presented.
