Concealed holographic coding for security applications lay using a moire technique
- 物理技术－已发表论文 
We present an optical coding technique that enhances the anticounterfeiting power of security holograms. The principle of the technique is based on the moire phenomenon. The code in the hologram has a phase pattern that is invisible and cannot be detected by optical equipment, so that imitation is extremely difficult. Holographic, photographic, and embossing techniques are used in fabricating coded holograms and decoders. (C) 1997 Optical Society of America.