Ultrahigh-Density Recording Technologies

Abstract

Magnetic recording and optical recording are the major technologies used to provide long-term storage of information in today's computer systems. Magnetic recording has been used for data storage in computer systems for over 40 years, and the advances in technology that have occurred in that time frame are nothing short of phenomenal. One might expect that after 40 years of dominance, the rate of progress in magnetic recording would be slowing down and that other technologies would be moving in to replace it. However rather than slowing down its rate of progress, magnetic recording is now advancing at a faster rate than at any time in the past. Magnetic hard-disk drives represent the largest segment of the data-storage business, and the number of hard-disk drives sold is increasing at about 20% per year. Tape drives continue to enjoy a very substantial market and are also advancing at a rapid pace while flexible disk drives continue to appear in every personal computer sold and have recently increased capacity by nearly two orders of magnitude.Optical recording was introduced into the marketplace in 1989 and has secured a significant market. However thus far, optical recording has primarily found new market niches, rather than being directly competitive with magnetic recording. CD-ROMs are widely used for the distribution of prerecorded information—a business that is now comparable in size to the magnetic-tape-drive business. On the other hand, erasable, optical drives, which were first introduced in 1989, have not had nearly as much success and have much smaller markets than either magnetic hard drives or tape drives.