Fourier holograms recorded and decoded in polychromatic light

This paper describes a recording and reconstruction method applied to two-dimension Fourier holography, in which the illumination at the recording stage is spatially coherent and temporally incoherent. The various chromatic components of the information to be recorded in the hologram are spread along a direction orthogonal to the entrance slit of a spectroscope that behaves as scanning pupil performing a chromatic coding. The message, both spatially and temporally coded, can be reconstructed by using a conventional process, the light source being still polychromatic.