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How Holographic Storage Works
The Chef writes: "Tweak3D.net has yet another excellent article for nerds -- err, I mean, guys looking to fill their brain with technical know-how. This time it's on holographic storage for PCs. Yeah, that's right -- storing files using holography! Go here for the story." This is something that gets mentioned in passing frequently but it's nice to have the technology explained nicely. Thanks for the overview!
2. The vast majority of people have never been victims of violent crimes.
I KNOW THIS, THATS WHY IT'S FUNNY. Or at least its supposed to be. When I heard that I laughed out loud, since it was such a stupid thing to say. No one gets it, though. So I'm going to start using my next favorite CNN quote: "We don't know how bad things are in north korea, but here are some pictures of hungry children. -- CNN "
Sheesh, people.
We don't know how bad things are in north korea, but here are some pictures of hungry children. -- CNN
ReadThe ReflectionEngine, a cyberpunk style n
If they achieve the 10 Gb/cm capacity like they are forecasting, then finally I will be able to have the a (insert favourite MP3 player) that can hold a decent amount of MP3s
Access times all depend on the sort of retrieval you're going to use. One system proposes using sound waves to cause different oscilations in the crystal letting to hit it at different angles with a reference beam. Instead of holographic storage replacing RAM I think we'll see it start replacing magnetic storage. Once refined the components to read and write a holographic cube would cost about as much as a good CD-ROM drive with the cubes not costing too much because they can be easily mass produced. With 10GB per cubic centimeter it isn't hard to imagine larger crystals holding 100GB or more.
I'm a loner Dottie, a Rebel.
The external hologram surface may indeed be sensitive to damage. This is why Harddrives come packaged inside of metal cases. Sunlight would be blocked out as well. Additionally, magnetism, which damages non-optical drives, would not harm this drive. Generally speaking, optical storage devices have always been more reliable then magnetic media. You didn't learn much about holograms when you made one in 1977, because much of what you said here is wrong. As an explorer, you probably made a reflecting-light hologram, similar to what is on a VISA card. These are inaccurate as the picture changes depending upon the angle and colors of light reflecting upon the foil. Using a transmission-light hologram is much more accurate. When a monochromatic light source (expanded laser) shines upon the film, the original image is created in 3 dimensions. The image is very insensitive to precise alignment of the lasers. The laser can be angled within a range of more then 10 degrees. The film can hold more information then one 3-D image. This is what IBM is refering to. Additional monochromatic light sources can store multiple images in the film, each constructing a 3D image when transmitted through the film. After too many images are added to the film, it can't reconstruct images as well. Think of this as overexposing regular film, it's almost similar to this. The solution to this is not to have many images. One true 3D image (which holograms construct - not false ones like 3D glasses construct) already holds much more information then it's 2D counterpart. I'm a little unsure about the practicality of a holographic drive in the near future, but IBM is known for applying it's research to products. The copper technology and advanced layering of ceramic insulaters/semiconductors are examples of this. Holography has already met and surpassed traditional optical methods when it comes to nondestructive testing.
I recommend Optical Methods of Engineering Analysis by Gary Cloud for more reading in the area of holograms and how/why they work. This book is very applied and mentions many practical examples of holograms in industry.
Finally, my grammar nazi side is pointing out that you misspelled manufacturing. It's late and I probably misspelled more then just that, so I forgive you.
Keeping
Seriously though I see to recall an article back in the old, dead tree edition. Er, just a sec
...Man, I wish all the magazines had archives as complete as the old Byte ones. Anyhoo, they have a couple links about holographic storage there too:
1996 and 1998
Not bad, but essentially saying the same thing as the tweak3d article. Some of the other, non-holographic versions of storage sund like they may actually see the light of day first.
--sugarman--
One possible answer is because of the sensitivity of holographic equipment to vibrations. A hologram encodes phase differences between laser beams. Errors in the phase encoding mean errors in the data retrieval - you get a blurry or disjoint hologram, or you lose your data.
Light is in the hundreds of nanometers range of wavelength. This means a vibration in the equipment (a movement of one part relative to another) of only a tenth of a micron can completely throw the phase encoding out of alignment. Imagine a tape deck whose heads needed positioning to submicron precision.
Making holographic images is therefore rather difficult if, say, a large lorry rolls past your window. A hard-drive with the same problem would be absolutely useless.
So until a suitably hard substrate can be found on which to engineer this equipment, it's only a pipedream. Maybe nanotechnology will create such a material ... I doubt it'll happen before then.
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It's a
-- Danny Vermin
Wonderful article. I'm so glad /. still posts stuff like this occasionally.
The author mentions, enticingly, that the potential of the technology is to store 10 gigs or more in an area roughly the size of a "single gambling die". This, clearly, is a fantastic dream.
Regrettably, the real problem that the article doesn't really touch is the space and more importantly, the precision and energy, required by the laser that is needed to read and write to the medium. Just glancing at the interior of my relatively rudimentary CD-ROM drive, I can see that its mechanism consumes considerably more area than a die. And it doesn't even rely upon the sophisticated network of lenses described in the PRISM research project.
You all know how inconvenient it was/is to transport a CD player through rough terrain and expect it to work continuously. Imagine trying to get any kind of ruggedness out of this badass!
However, 10 gigs smaller than the last joint in my thumb.... yum.
-konstant
Yes! We are all individuals! I'm not!
-konstant
Yes! We are all individuals! I'm not!
Finally a really good article about holograms in general and holographic storage specifically. Most people are not really aware how close many companies are to production of holographic storage. While magnetic hard drives are getting really dense they are still overly mechanical which adds greatly to their price. A holographic drive that would fit into a 3.5" internal bay could hold easily more than 100GB of data and have few or no moving parts. This means a greater mean time between failure and much less power consumed by the system (so we can power our GeForce 7s and Voodoo 9s). Besides desktop and server storage you could have a shitload of information encoded into a small plastic chip on a driver's license or credit card. The next generation of smart cards could carry user preferences for various computers, personal files, and cryptographic signatures. On top of that you can stick holographic drives in TiVo like toys or portable MP3 players. A single memory card the size of a sony memory stick (which is some of the best looking portable media ever) could hold a week's worth of music or an entire HDTV quality movie. How about a Palm XV with a gig of storage, that would be something to show off at an office party. Wow, I seem to have wet myself.
I'm a loner Dottie, a Rebel.
I think its time the penguins said-So long and thanks for all the fish-
lick the cancle button (at least thats what our Chinese QA says)
Perhaps in the next five years we will see the advent of the non-spinning drive, and portable disk space approaching the petabyte. Enough storage to keep most of what we now consider to be human knowledge.
Maybe it's enough to keep most of human knowledge on it, but I bet M$ can still come up with an OS that will fill most of that storage capacity.
Of course this has been predicted for a while. OD course they kept saying we'll have it soon and then not coming through. Same with a lot of stuff. Still, the engineers usually get it right in the end. But it's always later than they said it would be. 2003 seems a little optimistic t'me.
"If God created us in his own image, we have more than reciprocated"
The slashgods repeatedly rejected a submission about a scientific american article that talk about upper limits on magnetic storage and puts forth a marvelous discussion of holography (http://www.sciam.com/2000/0500iss ue/0500toig.html). My question is, why this article and not the other? I personally preferred the Scientific American article.
"Computer Science is no more about computers than astronomy is about telescopes."
-E. W. Dijkstra
1.Sure have. However, keep in mind that the astronomical speed at which computer tech has been developing for the last 30+ years is all quantitative growth. The basic concepts of hardware design haven't changed dramatically, we can just do it bigger, faster, cheaper... What we're looking at with holographic "disks" is a quantitative change... and that's going to be slower. It's like saying back in 1920 "We've had super-fast trains for years, and look how fast the automobile is developing... what the hell is taking those aeroplane guys so long?"
2. The vast majority of people have never been victims of violent crimes.
3. The vast majority of people who support the death penalty have never been falsely arrested/chagred/convicted of any crime.
4. Columbia University Law department study of all dp convictions since 1977 shows 68% were "seriously flawed" (read: mis-convicted) cnn blab here
2 1337 4 u!
I do not in any way mean to detract from the accomplishments presented here (though, of course, it's been presented in varying shades of "Any time now" for decades. I made my first hologram as a Explorer scout in 1977 or so, and at that time it was already a staple of such classics as "The Adolescence of PI")
However, the storage capacity cited is 10GB/cm^3 cubic centimeter) not cm^2 (square centimeter) as you stated. By comparison, given how thin the magnetic films are, I doubt the 75GB HDD even has 1 cc of active storage volume so holograms do not approach the volumetric density of magnetic media.
The key of course is that holograms offer the promise of true volumetric storage, where magnetic media is limited to the thin film [though who can forget the hedelberg group who used a thin film -- namely a roll of commercial adhesive tape to as an optical medium for up to 10GB a few minths ago?)
So, since it comes down to form factor, I'm not excited. The problem with the HDD is the overall associated mechanism, and with 1 GB matchbook 10G-resistant HDDs out there *today*, I'm not sure when I'll ever be excited. There is no reason to expect we'll be carrying 'naked' (or packaged) holographic media, any more than we carry naked (or packaged) *high density* platters today -- and holographic drives may well be larger, more expensive, more fragile, etc. than HDDs in 2003, as well. In 2003, you won't be able to *buy* a new HDD as puny as 10GB, if indeed they are still maanufacturing that size, today.
The external hologram surface may turn out to be sensitive to damage (though I can hope for the use of confocal optics, etc. to image the volume despite surface imperfections or contamination) and the volume may be vulnerable to sunlight.
The hologram technology used here showed promise because it can be multiplexed with different laser colors and at different angles, but the 'clarity' of the signal goes down with the square of the number of channels, until it is unintelligible. This does not bode well for rapid breakthroughs (though if we could predict them, they wouldn't be breakthroughs). Precise alignment is necessary to assure high density, reliable readings. it seems likely that the 2003 holographic drive will be larger, more expensive, and offer no appreciable advantage (aside from ?magnetic insensitivity?, if that counts)
Aside from the probability of actually seeing a production drive someday, I think that several other holographic technologies are more promising. and none of the holographic technologies show signs of exceeding the practical capacities of straight optical media in the predictable future -- i.e. the next three years. Standards, not technical capabilities, block DVD-R from coming out *this year*
Hey, I want my petabyte encrypted keychain as much as the next guy... but, you know, 'fire' still has many unparalleled uses, in the nuclear age. And I'd rather grill than irradiate my dead cow this weekend anyway
If you can go to bed, knowing you did a valuable thing today, you're very lucky. If you can't... it's not bedtime
Maybe so, maybe so. Can we get some articles about SERIOUSLY cool stuff that will occur in this decade?
Fawking Trolls!
"Going to war without France is like going deer hunting without your accordion." - Jed Babbin
is that you have to outfit your computer with special paper 3d glasses. one side red, one side blue!
FluX
After 16 years, MTV has finally completed its deevolution into the shiny things network
"It is seldom that liberty of any kind is lost all at once." -David Hume
The, um, backup crystal is almost full...
inspired by this paragraph.
However, as you keep recording more data pages slightly away from previous pages, the holograms will begin to appear dimmer and fogged up because their patterns must share the material's finite dynamic range and the data page is physically etched into the crystal. Eventually you will run out of space to store because the crystal has depleted all of its physical storage capacity, sort of like write once, read many media such as CD-R.
This is how they get so much data, you can shift the angle ever so slightly and have a new canvas. Mix this with a billion nano-bots with flashlights and miniature crystal-zamboni's and you've got some serious disk space.
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+&x
I see a lot of info about information density and price points, but what about access times? How long can we expect data requests to take? I understand that this is all still in its infancy, but I'm just interested in orders of magnitude. I would assume that it's faster than magnetic media requiring moving parts, but how does it compare to RAM and other silicon storage?
"You can never have too many elephants on your team."
The main problem with holographic storage is creating a usable and stable reader/writer. People have managed to create holographic storage devices from such fanciful things as spinning glass rods and tanks of supercooled gel
By the way
There have been some recent advances in fixed holographic storage, which would allow a 1-6 terabyte hard disk to be made, with no moving parts. However, the cost/gigabyte is still well over that achievable by magnetic media (but under that of copper memory).
Perhaps in the next five years we will see the advent of the non-spinning drive, and portable disk space approaching the petabyte. Enough storage to keep most of what we now consider to be human knowledge.
Reach out, extend to, and embrace the universe.
-Einstien
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Embrace, extend, and engulf the universe.
Reach out, extend to, and embrace the universe.
-Einstien
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Embrace, extend, and engulf the universe