ABSTRACT
Holography is also able to realize and modify complex amplitude characteristics in spatial frequency filtering and therefore bring us a big progress in optical computing technology. This chapter presents a digital version of the holography, called the digital holography. It discusses computer-generate hologram to generate complex amplitude filters with complexity and 3-D display of non-existing objects. The computer-generated hologram (CGH) can be synthesized by only computational procedures. The technique of computer-generated holography is widely used to reconstruct non-existing objects, to synthesize spatial filters with complex characteristics, to generate wavefronts with ideal shapes which are difficult to be fabricated by conventional methods, and so on. Cell-oriented and point-oriented CGHs are commonly used hologram formats. The phase-only optical element generated by a computer is called a kinoform, whose diffraction efficiency is higher than the conventional CGHs. The kinoform can include the reconstruction noise caused by the amplitude variation neglect and the phase quantization.
