Computer generated hologram of asymmetry franctional Fourier transform

A new optical encryption technique based on computer-generated hologram of asymmetry fractional Fourier transform is presented.In this method,the fractional Fourier transform hologram of original object with diff erent orders on axis x and y was coded and ploted into computer-generated hologram.In order to reconstruct the encoded image,special fractional Fourier transform systems with certain orders were needed.Because of its particularity of image reconstruction,it was regarded as a new optical security system and could be used in anti-counterfeiting.Computer simulated results show that this met hod can greatly improve the quality of security and anti-counterfeiting,at the same time practical application is more convenient compared to conventional encr yption technique,hence it has wide application and prospect.