Demonstration of color encrypted computer-generated hologram for an error-free optical ID tag system

In this paper, a color encryption method for an amplitude and phase modulated computer generated hologram (APM-CGH) for use in an error free optical ID system is proposed to overcome a weakness of the binary APM-CGH method. As a result of this method, the reconstruction errors caused from the image resolution problem can be reduced and data capacity can be increased by using a color tetramer encryption technique. It is shown that the color encrypted APM-CGH, in a comparison with the conventional kinoform-CGH, shows dramatically faster pattern generation times and more robust reconstruction capabilities against irregular pattern losses.