Top illuminator design for 2-D parallel readout in a 3-D multilayer optical data storage system

To achieve very high data rates in 3-D multilayer optical data storage systems, a novel approach is investigated to read out in parallel multiple tracks at different layers simultaneously. Data bits at different layers are arranged as titled data pages inside the disk. A uniform optical beam sheet is generated to illuminate the desired data page from the top of the disk, and a depth transfer imaging system is used to collect the fluorescence of the written bits within the data page to a detector array. The performance of the illumination optics has been experimentally evaluated and optimized by aberration compensation and equalization of irradiance distribution on the entire data page. Other important factors including reflection loss, sensitivity to disk quality, and servo requirements of disk wobbling are analyzed.