Holograms, not just for storage anymore

A recent article I read (Holograms put storage capacity in a spin) discusses a novel approach to holographic data storage, this time using magnetic spin waves to encode holographic information on magnetic memory.

It turns out holograms can be made with any wave like phenomena and optical holograms aren’t the only way to go. Magnetic (spin?) waves can also be used to create and read holograms.

These holograms are made in magnetic semiconductor material rather than photographic material. And because the wave nature of magnetic spin operates at a lower frequency than optics there is the potential for even greater densities than corresponding optical holographic storage.

A new memory emerges

The device is called a Magnonic Holographic Memory and it seems to work by applying spin waves through a magnetic substrate and reading (sensing) the resulting interference patterns below the device.

According to the paper, the device is theoretically capable of reading the magnetic (spin) state of hundreds of thousands of nano-magnetic bits in parallel. (Let’s see, that would be about 100KB of information in parallel). Which must have something to do with the holographic nature of the read out I would guess.

I haven’t the foggiest notion how all this works but it seems to be a fallout of some earlier spintronics work the researchers were doing. The paper showed a set of three holograms read out of  grid. And the prototype device seems to require a grid (almost core like) of magnetic material on top of the substrate which is the write head. Not clear if there was a duplicate of this grid below the material to read the spin waves but something had to be there.

The researchers indicated some future directions to shrink the device, primarily by shrinking what appears to be the write head and maybe the read headseven further. It’s also not clear what the magnetic substrate which is being read/written to and whether that can be shrunk any further.

The researchers said that although spin wave holographics cannot compete with the optical holographic storage in terms of propagation delays and seems to be noisier, spin wave holographics do appear to be much more appropriate for NM scale direct integration with electronic circuits.

Is this new generation of solid state storage?

Photo Credits: Spinning Top by RusselStreet

GE Research announces new holographic media

HoloDisc1 (from http://www.gereports.com website)
HoloDisc1 (from http://www.gereports.com website)

When last we discussed holographic storage it was over the decline of the industry as a whole and what could be done about it.

Perhaps I posted too soon.  GE research just announced that they have come out with a new media formulation offering the possibility of 500GB per single disk platter and broadens the holographic storage ecosystem.

GE also mentioned that there was no need for the holographic storage to be in the form of a disk.  InPhase Technologies also had talked of other form factors besides rotating media.

Do rectangular form factors make sense?

Some of these non-disk form factors remind me of the storage cards in StarTrek or memory cards for old programmable electronic calculators.  But can they gain any traction?

The only reason a disk makes sense is that with rotating media the heads need only travel in one direction (in an arc with today’s magnetic disks, in an line with today’s CDs and DVD devices) to access a track of data.  The rotation of the platter would move all the rest of the data on a track underneath read-write heads.

With a card or any other rectangular form factor, heads and/or media would also need to travel in at least two directions to access data. Of course magnetic tape is a rectangular form factor, and today tape heads move in a single dimension (across the tape width) while the media flows under the heads in an complementary direction, linearly.

So would some form of holographic optical tape make sense. Probably, but the multiple layers needed for holographic storage will require some amount of depth to make it dense enough.  Tape’s current volumetric density may be hard to exceed substantially with this multi-layer optical media.

On the other hand, cards could be inserted into a card reader to supply one of these two directions for data access. But this may be hard to do manually at the fine grained track and/or data cell dimensions of today’s data density.  Hardware to automatically move the cards down a track of data can certainly be done it just takes technology.

Holographic disks

All that seems to show that disks probably make more sense.  The fact that with GE’s new media, holographic disk drives could read/write todays CDs, DVDs, and BlueRay disks would make it much easier to gain market traction.

With GE’s entry into holographic storage they are also possibly looking to use the technology for medical imaging.  At the densities being discussed, lots of x-rays, CAT scans, MRI scans, etc. could easily fit on a single piece of holographic media.


As an industry we have been talking about Holographic storage since the early 90’s.  The promise of this technology has always been significant more data per square inch than currently available technologies.  But it has been a difficult technology to get to work properly.  There’s just a lot of technology that has to be mastered to make it happen, e.g., media, heads, page digitizers, etc.

Nevertheless, holographic storage continues onward.


Whatever happened to holographic storage?

InPhase Technologies Drive & Media (c) 2010 InPhase Technologies, All Rights Reserved (From their website)
InPhase Technologies Drive & Media (c) 2010 InPhase Technologies, All Rights Reserved (From their website)

Although InPhase Technologies and a few other startups had taken a shot at holographic storage over time, there has not been any recent innovation here that I can see.

Ecosystems matter

The real problem (which InPhase was trying to address) is to build up an ecosystem around their technology.  In magnetic disk storage, you have media companies, head companies, and interface companies; in optical disk (Blu-Ray, DVDs, CDs) you have drive vendors, media vendors, and laser electronic providers; in magnetic tape, you have drive vendors, tape head vendors, and tape media vendors, etc.  All of these corporate ecosystems are driving their respective technologies with joint and separate R&D funding, as fast as they can and gaining economies of scale from specialization.

Any holographic storage or any new storage technology for that matter would have to enter into the data storage market with a competitive product but the real trick is maintaining that competitiveness over time. That’s where an ecosystem and all their specialized R&D funding can help.

Market equavalence is fine, but technology trend parity is key

So let’s say holographic storage enters the market with a 260GB disk platter to compete against something like Blu-ray. Well today Blu-ray technology supports 26GB of data storage in single layer media, costing about $5 each and a drive costs about ~$60-$190.   So to match todays Blu-ray capabilities holographic media would need to cost ~$50 and the holographic drive about ~$600-$1900.  But that’s just today, dual layer Blu-Ray is available coming on line soon and in the labs, a 16-layer Blu-ray recording was demonstrated in 2008.  To keep up with Blu-ray, holographic storage would need to demonstrate in their lab more than 4TB of data on a platter and be able to maintain similar cost multipliers for their media and drives.  Hard to do with limited R&D funding.

As such, I believe it’s not enough to achieve parity to other technologies currently available, any new storage technology really has to be at least (in my estimation) 10x better in costs and performance right at the start in order to gain some sort of foothold that can be sustained.  To do this against Blu-ray, optical holographic would need to start at 260GB platter for $5 with a drive at $60-$190 – just not there yet.

But NAND Flash/SSDs did it!

Yes, but the secret with NAND/SSDs was that they emerged from e-prom’s a small but lucrative market and later their technology was used in consumer products as a lower cost alternative/lower power/more rugged solution to extremely small form factor disk devices that were just starting to come online.  We don’t hear about extremely small factor disk drives anymore because NAND flash won out.  Once NAND flash held the market there, consumer product volumes were able to drive costs down and entice the creation of a valuable multi-company/multi-continent ecosystem.  From there, it was only a matter of time before NAND technologies became dense and cheap enough to be used in SSDs addressing the more interesting and potential more lucrative enterprise data storage domain.

So how can optical holographic storage do it?

Maybe the real problem for holographic storage was its aim at the enterprise data storage market, perhaps if they could have gone after some specialized or consumer market and carved out a niche, they could have created an ecosystem.  Media and Entertainment has some pretty serious data storage requirements which might be a good match.  InPhase was making some inroads there but couldn’t seem to put it altogether.

So what’s left for holographic technology to go after – perhaps medical imaging.  It would play to holographic’s storage strengths (ability to densely record multiple photographs). It’s very niche-like with a few medical instrument players developing MRI, cat scans and other imaging technology that all require lot’s of data storage and long-term retention is a definite plus.  Perhaps, if holographic technology could collaborate with a medical instrument consortium to establish a beachhead and develop some sort of multi-company ecosystem, it could move out from there.  Of course, magnetic disk and tape are also going after this market,  so this isn’t a certainty but there may be others markets like this out there, e.g., check imaging, satellite imagery, etc.  Something specialized like this could be just the place to hunker down, build an ecosystem and in 5-7 years, emerge to attack general data storage again.