Present Performance Future Directions in Two-photon Addressed Write Once Read Many Volumetric Optical Disk Storage Systems

摘要

Present performance in experimental two-photon addressed volumetric optical disk storage systems has been presented. The concept of 3-D parallel readout, simultaneous readout of multiple-tracks across multiple layers, has been presented and realized experimentally by utilizing a depth transfer optical system to image a tilted object plane of 64 digital data channels in a 4(layer) by 16(tracks/layer) to a tilted image/detector plane. The fluorescent spots at the detector plane were observed using a video microscope and observed to be of good quality. A PMT was scanned in the fluorescent image plane to measure the signal quality where crosstalk from adjacent tracks and adjacent layers was shown to be 25-30dB below the primary signal. A custom 64 channel CMOS detector array developed by Parallel Solutions, Inc, is integrated in the readout system providing a total readout data throughput of 64Mb/s.Influence of the numerical aperture on a 3-D multi-layer optical data storage system is analyzed based on simulation and experiments. A high NA objective lens decreases bit size, layer separation, and increases the volumetric capacity. Increasing NA also decreases the required recording laser power for two-photon absorption recording. Our extrapolation based on present experimental results indicates that 1TB/disk capacities are well within the capabilities of two-photon recorded volumetric disks.