Analysis of readouts in photochromic multi-wavelength memory

Although diffraction analysis of photochromic multi-wavelength optical disks becomes increasingly essential, traditional diffraction theories are not applicable to it, because they are not pit/land-recorded as these theories assume. With the disks modeled as transmittance-relief gratings and the information character as the convolution integral of a round spot and the track of the writing spot, the diffraction theory of readouts in photochromic multi-wavelength memory is achieved based on Fourier transforms and superposition method, by regarding the transmittance distribution to a certain wavelength as the summation of each photochromic layer's transmittance distribution. Utilizing Matlab programs and real experiments, readout curves in photochromic multi-wavelength memory are achieved and compared.