Method for increasing the diffraction efficiency by correlation filtering

It is necessary to increase the diffraction efficiency of hologram filters when data are processed by the correlation method. It is shown how this can be done by repeated use of the zeroth diffraction order of hologram filters. The signal/noise ratio for one-object and many-object filters is considered for the case of the simplest objects and an optical system is suggested for the implementation of the proposed method. The results of an experimental check are also given.