digitaldingus Article

Magneto-Optical Storage
The UnSub Storage System

January 11, 2006


Magneto-Optical storage systems have been around for quite some time but have not penetrated the consumer market like the average 3.5" hard drive has. Medical institutions, US military facilities, and many businesses use the MO technology to reliably backup important documents as additional and preventative measures for retaining confidential information. However, the average consumer has historically not purchased MO technology to benefit their own storage system.

In this article, we're going to take a look at MO technology, and how its reliability is actually just as good as...and better, than the average 3.5" hard drive.

Magneto-Optical Technology

Basically put, a laser beam (tuned at around 680nm and 0.7 microns in diameter) is projected onto the media disk (made mostly of polycarbonate), where the beam heats a particular layer on the disk to Curie Point (the temperature at which a magnetic substance loses its coercive force, which is 200° C), thereby enabling the magnet within the drive itself to easily contour the polarization of the disk. Once this is done, the drive can quickly switch the polarization of the magnet, creating a data mark on the disk. When reading a disc, the laser beam is polarized and the reflected light is interpreted into data.

MO Technology is kind of like a cooking recipe. For example, to make different shapes of candy, you have to heat the sugar to a point where you can move the candy base around and shape it with your hands or molds, before it gets cold. This is what the laser inside MO drives are doing. They are heating up an area on the disk so that when a magnet is brought within a specific distance, the magnet can change the properties of the disk. Then, when the disk is not in use, the disk is "hard", and is able to be read over and over without fear of data contamination due to the way it was recorded.

Reliability Of MO Technology

Each MO disk is certified to be read over 1,000,000 times. Now, chances are, you will be moving your data off an MO disk before you reach the one-million mark. And even if you do not, chances are again you probably won't have even reached the half-way point.

In addition to the high repetitive rating of the MO disks, the disks also have high tolerances to temperature. The Curie Point of MO disks is 200 degrees centigrade, which means anything below that temperature will not affect the data on the disk. Try to operate a typical hard drive in temperatures like these. We're talking 392 degrees Fahrenheit.

Why Is MO Technology Mostly Unknown To The Consumer?

For a technology which is superior and more reliable than the current hard drive in your computer, this is certainly an interesting question. However, we find the answer in terms of marketing sensationalism over the years. MO Technology is not as dynamic as regular magnetic drives, and currently do not have the ever-increasing capacities as a typical 3.5-inch magnet drive over a short timespan. 500 Gigabyte drives are now found online and in your favorite computer store. But try to find a Fujitsu MO drive and you'll receive several scratchings of the head from sales associates when you mention the technology and the model numbers.


It's simple marketing and what sells. Larger numbers sell. Why buy a drive for $280 and a 5-pack of 5-2.3GB MO disks for another $100, when you can buy a 300GB hard drive for around $250? It's that kind of thinking which can get you into trouble. Many of us need to understand that smaller capacities can actually be better for us, and actually cost us less money in the long run.


Fujitsu DynaMO 2300U2

Drive: MDG3230UB
Released: January 2002
Interface: USB 2.0 (or earlier)
Data Transfer Rate : Up to 8.38MB/s using 2.3 GB GIGAMO
Average Seek Time: 19 ms
Rotational Speed: 3637 rpm (GIGAMO disks)
Buffer : 7.6 MB
Input Power: 100 - 240 VAC, 50/60 Hz
Power Consumption: 15 W (max)
Dimensions: 122 mm (W) x 162 mm (D) x 34 mm (H)
Weight (Drive): 630 g
Current Price: NA

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