The 3D image can be reconstructed by shining the reference beam or a beam related to it onto the hologram and by perceiving the diffraction beam. That way, the reference beam serves as a reading beam, whereas during the recording of the hologram it was a writing beam. The reconstructed image is a true 3D image in space which the viewer can look at from various perspectives. The images will be projected by lenses. As lenses are able to perform the inverse Fourier transform, holograms can also be stored directly as a Fourier transform. When the hologram is read out onto a lens, that lens provides the original image. This opens up the way for computer-generated holograms, where computers perform the algorithm for the fast Fourier transform (FFT) of an image. A hologram can be used as a screen for image projection.

Controlled Vocabulary Terms

fast Fourier transforms; holography; three-dimensional displays