Study of coding principle and detecting technology of diffractive composite spatial code

Diffractive composite spatial code is a novel concealed optical code. It use diffractive micro-gratings matrix as carrier of diffractive composite spatial code. When diffractive micro-gratings matrix is lighted with monochromatic plane wave, diffractive composite spatial code appears. With the aid of specific recognizer, meanings which diffractive composite spatial code represents will be read out. Coding principle and design ofdiffractive composite spatial code are introduced in details in this paper. Detecting technology of this code is explored, too. The analyzing indicates that the method of recognizing of diffractive composite spatial code is unsophisticated and feasible. These characteristics are very important and useful in security of document, bond and even web.