Photoelectric recording of optical fields by correlation processing

A theoretical and experimental investigation is made of the photoelectric recording and separation of a signal from a noise background by correlation processing of information carried by the optical fields. The Fourier transformation is operated by an optical method. Filtering and the inverse Fourier transformation are performed to obtain the correlation function during the recording process by using a transient reference wave with a linear frequency variation over its cross section and containing a spatial filter. This wave is formed by the quasilinear motion of a filter in the focal plane of a lens. The signal is recorded on an oscillograph screen.