BY LISA COLEMAN
This year, magneto-optical (MO) technology reached a milestone on the Optical Storage Technology Association (OSTA) road map when 130mm 9.1GB (14X) products started shipping.
"Users can now take advantage of higher-capacity, higher-performance disks without obsoleting their existing 5.2GB and 2.6GB disks," says Dan Dalton, chairman of OSTA's high-performance subcommittee.
This summer, the European Computer Manufacturers Association (ECMA) expects to approve the 9.1GB standard, which means that any 130mm 9.1GB MO disk should work in any 130mm 9.1GB drive. To achieve the 9.1GB capacity, manufacturers had to overcome a few technological hurdles, including magnetic-induced super resolution (MSR) and land-and-groove recording. MSR allows a drive to read a very small written mark. The size of the mark is smaller than the diameter of the laser spot used to mark the media. MSR technology creates thermal masks that allow the drive to "resolve" these small written marks and eliminate bit-to-bit and track-to-track interference.
The magneto-optical (MO) road map, developed by the Optical Storage Technology Association (OSTA), reached the 9.1GB milestone this year.
Land-and-groove recording is a new technique for recording on both the grooves on the disk (a technique used in conventional MO recording), as well as recording on the lands between the grooves. This enables data to be packed in a much higher areal density (almost 2X).
Key 9.1GB MO technology features include
- Magnetically induced super resolution;
- Land-and-groove recording;
- Data transfer rate of up to 6MBps;
- 25ms average seek time; and
- 75% increase in bit density from previous 5.2GB technology.
Since the debut of 650MB, 130mm MO in 1998, the technology has made steady improvements in capacity (see chart). The next step beyond 9.1GB is 20GB. Currently, MaxOptix is developing an Optical Super Density (OSD) drive for 20GB capacity on a single, double-sided disk. While MaxOptix is working on this MO technology, Sony has announced that it is working on a non-MO technology called Ultra Density Optical (UDO), which targets 40GB capacities for first-generation products. UDO will use violet lasers to increase density and data transfer rates.