The light efficiency of computer generated Fourier holograms is compared for different amplitude distributions of the filter function. Then a tandem configuration with two separate phase filters is discussed. It allows a general wavefront modification with very high light efficiency.
"Efficiency And Versatility Of Computer Generated Holograms", Proc. SPIE 0437, Intl Conf on Computer-Generated Holography, (26 October 1983); doi: 10.1117/12.937123; https://doi.org/10.1117/12.937123