The transmission of information by coherent light. III. Speckle noise

For pt.II, see ibid., vol.8, p.161 (1975). Speckle noise arises when coherent radiation of any kind is used in an instrument. It can be both subjective (formed in the detector) or objective (in the beam itself). A theoretical description of speckle noise given here leads to a prescription for the elimination of both subjective and objective speckle in an important practical case-the diffusely illuminated hologram.