Optical data storage media

Abstract

In this paper, we review many of the technical issues that must be addressed in developing high-quality optical disk recording media. The geometric design of tracking grooves and embossed data on the disk substrate must be optimized to the characteristics of the optical drive to support robust data seeking, track following, and data addressing. To ensure adequate recording performance and drive compatibility, we have used modeling to optimize the media thin-film structure for proper optical, thermal, and magnetic characteristics. Because low substrate birefringence is a necessary media characteristic for high recording densities, we discuss measurements which assess whether birefringence has been adequately controlled in disk production. Testing is used throughout media development and manufacture to measure that the quality goals of the design are achieved. The mechanical integrity of the disk and its cartridge, particularly for autoload libraries, is confirmed by load/unload stress testing. Media life and data archivability are established by a combination of time-zero and accelerated life stress tests of media mechanical and recording performance. This attention to a broad range of technical details is essential to ensure reliable storage of data on removable optical disk media.