Originally posted by sonhouseWould you need a similar laser to read the disks?
It says the laser is a 405 nm wavelength but 100 WATTS with 3 picosecond pulses and a prf of 1 ghz, 1 billion pulses per second to allow the creation of disks with 20 times the storage of present day blu-rays.
Originally posted by twhiteheadEven if it goes 3D, by which I assume you mean multiple layers so if one layer does 1 terabyte, then 10 layers and you are into some serious storage. This may be true but optical drives can't go anything like 7 or 10 K rpm so they are intrinsically slower drives.
Would you need a similar laser to read the disks?
Though I guess anything better than current blue ray capacity is not really of any use to the movie industry (as they would be hard pressed to sell you 20 HD movies at once).
It would be wonderful for backup purposes, but the market is probably too small.
I'm still waiting for laser storage to go truly 3D, then it can finally take over from the magnetic hard disk.
Originally posted by sonhouseIt is probably not possible, but I was thinking of vertical data density similar to the current horizontal density, so a 1 cm thick disk could store something like 1000 times what a current disk does (and read maybe 100 times faster, as it would mostly be the laser refocusing, not the disk moving.)
Even if it goes 3D, by which I assume you mean multiple layers so if one layer does 1 terabyte, then 10 layers and you are into some serious storage. This may be true but optical drives can't go anything like 7 or 10 K rpm so they are intrinsically slower drives.
I don't see optical drives competing with mags any time soon. They keep improving both optical and magnetic drives but so far mags win in total storage and speed.
Originally posted by twhiteheadAren't you thinking 1 mm thick disk? 1 cm is like a half inch. Also, what would you gain duplicating the technology with optical components vs magnetic components? The track finding system would be identical, there would have to be a mechanism for swinging a laser reflector back and forth, it would even be more complicated because it would have to have several reflective surfaces to guide a laser beam back and forth to it's laser/detector.
It is probably not possible, but I was thinking of vertical data density similar to the current horizontal density, so a 1 cm thick disk could store something like 1000 times what a current disk does (and read maybe 100 times faster, as it would mostly be the laser refocusing, not the disk moving.)
Also an optical drives speed limit is largely due to t to backup my whole hard disk occasionally, but DVD just doesn't have the capacity to do that.
Originally posted by sonhousewould welding goggles filter that wavelength out?
It says the laser is a 405 nm wavelength but 100 WATTS with 3 picosecond pulses and a prf of 1 ghz, 1 billion pulses per second to allow the creation of disks with 20 times the storage of present day ...[text shortened]... at!
I'll bet it could be used for that mosquito killer laser we read about a few weeks ago!
Originally posted by zeeblebotI'm sure it would, however, if left pulsing at a 1 ghz rate, it might drill right through it in short order! Maybe not, but it would be an interesting experiment. I would not want to wear one for that experiment however!
would welding goggles filter that wavelength out?
Originally posted by sonhouseI was more interested in whether the same laser would be required
In answer to the question about whether the same laser would be used to read the disk data, yes it would, same laser but lower power, high power to cause the phase changes on the media and lower power pulse to read which state the media is in, biphase, one phase being more reflective than the other so you get 1's and 0's. With the appropriate error correcting codes of course.
Originally posted by twhiteheadI think not. The problem is to get 20X the density, if you do the square root, each track would have to be about 1/5th the diameter of the old one and spaced much closer together. There would be 20 times the data, so a regular blu ray would not be able to jump from track to track, they couldn't track at all. Like an old time record player, a 78 rpm job trying to play a more modern vinyl 33 rpm record with much closer grooves.
I was more interested in whether the same laser would be [b]required
ie could the DVD makers have the latest technology lasers and create high capacity disks whilst the rest of us read the disks in our older technology blue ray drives (with modifications of course).[/b]
Originally posted by sonhouseNo, I really did mean 1cm. I was thinking of true 3D storage.
Aren't you thinking 1 mm thick disk? 1 cm is like a half inch.
Originally posted by twhiteheadI think 1000 layers right now is out of the question. They can do maybe 10 layers but to have a 1cm thick disk, the mass would lead to run out problems, which I saw up close and personal on a HD drive manufacturing line in Scottsdale, they required run-out (disk wobble) to be something like 50 microinches (just over one micron) and that is with a very thin glass disk. The rpms have to be very stable as well as the wobble to allow reliable tracking.
No, I really did mean 1cm. I was thinking of true 3D storage.
Current technology can store multiple layers (most movie DVDs are dual layer). I believe more layers have been achieved but not generally used.
What I don't know is how the drive changes layers. Does the laser have to physically move, or can the layers be read by refocusing the laser by some ...[text shortened]... alize it would never compete with magnetic storage, but it might be a better option for backup.
Originally posted by sonhouseYes I can see that the new laser is the way to go. Finally I will be able to back up my whole hard disk. But then again, by the time I actually have one of these new lasers, my hard disk will be 100 terabytes.
They can get a few layers now, say 4 max but it still uses one laser and therefore has to have a refocus assembly to get the focal point from one layer to another. Still with this new technology, 1 terabyte per layer is one heck of a lot of storage. Double layer goes to 2 terabytes, etc. Even one layer would be a serious amount of storage.
Originally posted by twhiteheadGood grief! 1 PETAbyte of storage. I would like to see that! 1000 Terabytes, 1,000,000 gigabytes! A billion megabytes. NASA could use that level of storage, they are getting gigabytes per day of data, they must be single handedly supporting the HD industry!
Having looked it up, I see I may not be so far off:
Go down to commercial development
The record so far seems to be 200 layers.
You may also find these interesting:
http://en.wikipedia.org/wiki/Holographi ...[text shortened]... back in 2007: