Reduction of noise in computer generated holograms

摘要

Noise is reduced in computer generated holograms (CGH's) by a method of overexposure. The CGH is used to make a master hologram. The master hologram is then used to make a copy from which a succession of other copy holograms is made. Each successive copy hologram is exposed less than the prior ones while increasing brightness uniformity. Consequently, a decreasing amount of change in exposure is required to reach 100% efficiency. The number and orientation of the copy holograms is incorporated into the design of the final optical element. The final hologram is not overexposed, since the amount of exposure has been reduced from the earlier holograms, and can be used in complex optical power systems.