Intersecting lasersPew pew! No, really - the process InPhase uses starts with a single laser, the light of which is first split into two beams, creating a 'reference' beam and a 'signal' beam. The signal beam shines through what's known as a spatial light modulator that introduces interference - aka encoded binary data - into the signal beam in the form of light and dark pixels. Data to be encoded is first mapped to 0s and 1s, and sent to the SLM, creating a binary checker-board of pixels that let through or block the light. Think of the SLM as a page of data, and the goal is to store millions of these pages within the recording medium. In fact, the volume of data encoded can depend on the size of the SLM, so the technology is easily scalable, but as a minimum is intended to encode at least one million bits per page. The encoded signal beam and previously split reference beam meet up again and intersect at the storage medium, where a chemical reaction in the light-sensitive substrate induces modulations in the refractive index of the material relative to the beams. And voila, a hologram of the SLM image is preserved. But that's just a single hologram isn't it? Indeed, and here's where it gets cooler - by varying the angle or wavelength of the reference beam, the content of the signal beam can be stored at different orientations in the medium, creating hundreds of unique holograms within the same area. According to InPhase, at one million bits per page the technology can store a 'book' of 252 pages layered 15 times in the one location. To read that data, a reference beam is shone through the recording medium at the same angle that was used to store a particular hologram. As it shines through it deflects off the hologram re-creating the signal beam in the process. A detector then picks up the light - which looks like the contents of the SLM that it represented - and decodes the information. And this is where another advantage of holographic storage kicks in: it's not just about storing large volumes of data, but at a million bits per hologram, data transfer is an order magnitude faster than anything we have today. In principle, the holographic drive is reading a million bits per laser pulse compared to your CD and DVD's one-bit per pulse. You do the math! And how much can InPhase's technology store in its disks? The first prototypes were aimed at big business, and so its commercially orientated product 'Tapestry' slaps this on the brochure: 300GB to 1.6TB per disk at up to 120M/s - that's as large as, and as fast as, a top-end 7200 RPM hard drive. All in a form factor similar to a DVD. However, those figures are apparently only the beginning with estimates of the potential for discs to carry 4TB or more. There are other benefits too. The bonded layers in CD, DVD and Blu-ray substrates are prone to decay - disc-rot as it is sometimes called - maybe lasting a few decades if looked after, but holographic discs, depending who you talk to, can have a purported shelf life of 50 years. As InPhase is happy to point out, the potential is enormous, stating that the technology can be applied to other form factors, and suggesting that you could store " 50 hours of high definition video on a single disk, 50,000 songs on a postage stamp, or 500,000 x-rays on a credit card." Wow, that's a lot of pr0n. When?Consumer level products from GE, InPhase or others are unlikely to appear for a few years yet. And, when they do, they will of course be obscenely expensive and only come down as adoption increases. As an aside, a standard for holographic discs has already been defined - called HVD - which revolves around a method called 'collinear holography' to store data. However two companies that were due to deliver products all the way back in 2006 based on this standard, Optware and Maxell, didn't eventuate. Three years later, InPhase appears the first to market with its method and technology, even if aimed at big business, while GE may well be first to target consumers. Still, just as with CD and DVDs before it, Blu-ray has a limited lifespan and the question isn't if it has a successor, but when its successor will be and in what form. And, for the money as it were, holographic storage is mighty promising and you may one day be buying a holographic drive for you machine. Put that in a sentence when you're talking about your next purchase. See? I said it sounds cool!
Intersecting lasersPew pew! No, really - the process InPhase uses starts with a single laser, the light of which is first split into two beams, creating a 'reference' beam and a 'signal' beam. The signal beam shines through what's known as a spatial light modulator that introduces interference - aka encoded binary data - into the signal beam in the form of light and dark pixels.
Data to be encoded is first mapped to 0s and 1s, and sent to the SLM, creating a binary checker-board of pixels that let through or block the light. Think of the SLM as a page of data, and the goal is to store millions of these pages within the recording medium. In fact, the volume of data encoded can depend on the size of the SLM, so the technology is easily scalable, but as a minimum is intended to encode at least one million bits per page.
The encoded signal beam and previously split reference beam meet up again and intersect at the storage medium, where a chemical reaction in the light-sensitive substrate induces modulations in the refractive index of the material relative to the beams. And voila, a hologram of the SLM image is preserved.
But that's just a single hologram isn't it? Indeed, and here's where it gets cooler - by varying the angle or wavelength of the reference beam, the content of the signal beam can be stored at different orientations in the medium, creating hundreds of unique holograms within the same area. According to InPhase, at one million bits per page the technology can store a 'book' of 252 pages layered 15 times in the one location.
To read that data, a reference beam is shone through the recording medium at the same angle that was used to store a particular hologram. As it shines through it deflects off the hologram re-creating the signal beam in the process. A detector then picks up the light - which looks like the contents of the SLM that it represented - and decodes the information. And this is where another advantage of holographic storage kicks in: it's not just about storing large volumes of data, but at a million bits per hologram, data transfer is an order magnitude faster than anything we have today. In principle, the holographic drive is reading a million bits per laser pulse compared to your CD and DVD's one-bit per pulse. You do the math!
And how much can InPhase's technology store in its disks? The first prototypes were aimed at big business, and so its commercially orientated product 'Tapestry' slaps this on the brochure: 300GB to 1.6TB per disk at up to 120M/s - that's as large as, and as fast as, a top-end 7200 RPM hard drive. All in a form factor similar to a DVD.
However, those figures are apparently only the beginning with estimates of the potential for discs to carry 4TB or more.
There are other benefits too. The bonded layers in CD, DVD and Blu-ray substrates are prone to decay - disc-rot as it is sometimes called - maybe lasting a few decades if looked after, but holographic discs, depending who you talk to, can have a purported shelf life of 50 years.
As InPhase is happy to point out, the potential is enormous, stating that the technology can be applied to other form factors, and suggesting that you could store " 50 hours of high definition video on a single disk, 50,000 songs on a postage stamp, or 500,000 x-rays on a credit card."
Wow, that's a lot of pr0n.
When?Consumer level products from GE, InPhase or others are unlikely to appear for a few years yet. And, when they do, they will of course be obscenely expensive and only come down as adoption increases.
As an aside, a standard for holographic discs has already been defined - called HVD - which revolves around a method called 'collinear holography' to store data. However two companies that were due to deliver products all the way back in 2006 based on this standard, Optware and Maxell, didn't eventuate. Three years later, InPhase appears the first to market with its method and technology, even if aimed at big business, while GE may well be first to target consumers.
Still, just as with CD and DVDs before it, Blu-ray has a limited lifespan and the question isn't if it has a successor, but when its successor will be and in what form. And, for the money as it were, holographic storage is mighty promising and you may one day be buying a holographic drive for you machine.
Put that in a sentence when you're talking about your next purchase. See? I said it sounds cool!
Issue: 133 | February, 2012