Investigation of certain diffraction effects in a double-layer optical disk

We study, both by computer simulation and experimentally, the diffraction of the incident beam from the grooved structure of the first layer onto the second layer of a double layer optical disk. We also examine the cross-talk between the focused-error signal curve obtained from the two layers. Good qualitative agreement is obtained between simulations and measurement. It is hoped that these and similar studies will enable us to estimate the magnitude of the noise caused by diffraction from one layer on the signal obtained from the other layer.