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New 100GB Optical Disk From Taiwan
Alt173 points to this article from Taiwan Economic News , excerpting: "The National Science Council (NSC) said Sunday that a local research team has successfully developed a new optical disc that can hold more than 100 gigabytes of information.
The research team was led by professor Tsai Ding-ping of National Taiwan University. The new disc can store 150 CDs of favorite songs or an equivalent of 20 DVDs, Tsai said.
By using "near-field" optical technology, the 100-gigabyte disc stores more than any other similar product in the world. The super-sized disc will be used at home to store large movie or music files, according to Tsai.
The near-field optical technology also allows the bits of information on a disc to be spaced closer together to increase the disc's storage capacity."
Summary
Constellation 3D's technology implements the concept of the volumetric storage of information. Data is recorded on multiple layers located inside a disc or a card, as opposed to the single or double layer method available in compact discs, and DVDs.
The recording, reading and storing of the information is accomplished through the use of fluorescent materials embedded in pits and grooves in each of the layers. The fluorescent material emits radiation when excited by an external light source. The information is then decoded as modulations of the intensity and color of the emitted radiation.
Background
It has long been recognized within the data storage scientific community that, 2-dimensional storage carriers are insufficient for future generations of memory devices. Research efforts have therefore focused on ways to develop 3-dimensional storage including holographic techniques and multi-layer storage as illustrated below.
The concept of multi-layer reflective optical discs has been proposed by Philips and IBM, and has been demonstrated up to several layers. In fact, DVD is an implementation of this concept with two layers.
However for many layers, the coherent nature of the probing laser beam causes interference, scatter and intra-layer cross talk - the combination of which results in a signal that is degraded to unacceptable levels. In addition, reflective multi-layer discs encountered considerable technological difficulties in manufacturing of media commensurate with the formidable requirements for optical quality. For these reasons research efforts into multi-layer reflective technologies have been abandoned.
The concept of multi-layer, fluorescent cards/discs (FMD/C) is a unique breakthrough, solving the problems of signal degradation associated with current reflective optical disc technologies of CD and DVD.
As with a CD or DVD, data on the FMD layers is encoded on a substrate in a series of geometrical features or volumetric marks. Each layer will have a capacity approaching 4.7 Gigabytes (as in the case of DVD).
With FMD/C technology, each storage layer is coated with a transparent fluorescent material rather than the reflective metallic layer of a CD or DVD. When the laser beam hits a mark on a layer, fluorescent light is emitted. This emitted light has a different wavelength from the incident laser light - slightly shifted towards the red end of the light spectrum - and is incoherent in nature, in contrast to the reflected coherent light in current optical devices. The emitted light is not affected by data marks, and therefore transverses adjacent layers undisturbed.
In the read out system of the drive, the laser light is filtered out, so that only the information-bearing fluorescent light is detected. This reduces the effect of stray light and interference. Theoretical studies, confirmed by experimental results, have shown that in conventional reflection systems the signal quality degrades rapidly with the number of layers. In fluorescent read-out systems, on the other hand, the signal quality degrades much more slowly with each additional layer. Research has shown that media containing up to a hundred layers are currently feasible, thereby increasing the potential capacity of a single card or disk to hundreds of Gigabytes. Use of blue lasers would increase the capacity potential to over 1 Terabyte.
Some of the technological advantages of FMD/ FMC products include:
Increased Disc Capacity
Initially, the FMD disc will hold anywhere from 25 - 140 GB of data depending on market need. Eventually a terabyte of data on a single disc will be achievable.
Quick Parallel Access and Retrieval of Information
Reading from several layers at a time and multiple tracks at a time - nearly impossible using the reflective technology of a CD/DVD - is easily achieved in FMD. This will allow for retrieval speeds of up to 1 gigabit/second.
Media Tolerances
By using incoherent light to read data the FMD/FMC media will have far fewer restrictions in temperature range, vibration and air-cleanness during manufacturing.
Usage Flexibility
FMD/FMC presents a wide variety of potential media sizes and types (read only, write-able and re-writeable) for a broad range of applications.
Potential for Further Growth
The technology is young and will grow and evolve, providing a clear road map for the future of data storage.
The FMD/C technology is presently protected by over 116 Japanese, European, and US patents, approved and/or pending, dozens of priority establishing disclosures, and the exceptional know-how of an unprecedented group of physicists cooperating across the world.
If you use Linux, please help development of Autopac
See 10 Terabyte 3.5" disk drive, here is your PDF. It might not be here yet, but it falls in the category of "optical" anyway. Also see this, they have existing demos.
Can someone explain what "near-field" optical technology is...
"Near field" means "close enough not to be able to treat the light as a propagating wave". More or less. Just "very close" in other words.
How the thing works....
You can't focus a beam of light to a spot smaller than a wavelength, but you can have a light source smaller than a wavelength, and you can see light through a hole smaller than a wavelength, so long as you're very close to the hole. Either of these methods can be used to illuminate a very small spot on a surface.
what makes you think that IDE can't handle? IDE, as much as SCSI, is a line-level protocol. Fibre channel, as much as firewire/usb is more of a connection medium/protocol, as it has the option to use SCSI as its actuall communication protocol. The limitations of YOUR IDE subsystem are likely from your IDE controller's bus speed, 33MHz, 66MHz, etc.
Furthermore, this article isn't talking *at all* about a drive mechanism, but rather a technology for the media. The media may be extraordinarily large, but the access to it may be slow, think tape drives - as they've gotten larger, sure, storing to them has gotten somewhat faster, but it still takes a few hours to fill up a 40GB/80GB tape.
This technology article is more concerned about talking about the expansion of how much data can be stored on one piece of media rather than how that data would be accessed, what applications that access speed would lend itself to, etc. The above post on FMC technology talks about speed-ups from using multiple lasers, each reading different tracks/layers - this would speed up access, otherwise, your only option is to spin a disk faster, which has certain practical limits.
Researchers develop new super-sized disc
The Taipei Times
y /0 000136369
o n. htm
http://www.taipeitimes.com/news/2002/05/17/stor
Bell Labs: Info on the technology itself.
http://www.bell-labs.com/new/gallery/bits.html
Homepage of Dr. Tsai's research group (contains Chinese characters)
http://pnstl.phys.ntu.edu.tw/english/introducti
-- Your local friendly mad scientist-in-training