Design and evaluation of a dual-beam read/write configuration for optical storage

Abstract

Increasing the number of read/write layers and ensuring the quality of read/write signals are the key factors to enhance the optical storage capacity. However, limited by the single optical path, the structure, and the material of the disk, the existing system reads and writes up to 16 layers. In the existing optical storage system design, the optical path design and the signal model are independent of each other, so the signal quality based on the signal model can only be evaluated after the implementation of the optical path. We propose a dual-beam read/write optical path for the optical storage system, which breaks through the limitation of the single optical path and can read/write multilayers. The servo detection signals and servo margins show that the dual-beam read/write system has good error detection capability and strong robustness. The servo error signal is calculated according to the relationship between the wavefront aberration, relative coordinate system displacement difference, and servo error of the optical system, thus deriving a quantifiable signal evaluation model. The effectiveness of the model is verified by experiments. The signal evaluation model breaks through the limitations of the traditional optical design method for the optical storage system and can guide the optical design from the signal perspective. The dual-beam optical path for multilayer optical storage systems provides a broader range of ideas for enhancing optical storage capacity.