Researchers condense entire image into single photon

A team of researchers has managed to find a way to store a large amount of data in a single photon of light. Although the first stored item -- an image of the characters "UR" -- implies that the inventor was a 13 year old girl dealing with an extremely low text messaging limit, the image was in fact intended to signify the institution which developed the technology, the University of Rochester (either that or it's the shortest example of the "UR IN MY ... " meme that we've seen in the while.) Apparently the system works because "instead of storing ones and zeros" (a la binary code), the team has figured out how to store an entire image in a single photon, which sounds sort of impossible to us. Funny, because that's exactly what John Howell, the leader of the team said about the system. One of the key components of the process is the particle-wave duality nature of light: by firing a single photon of light through a stencil -- we presume one heckuva small one -- the wave carries a shadow of the image along with it at a very high signal-to-noise ratio, even with low light levels. The light is then slowed down in a cell of cesium gas, where it is compressed to 1 percent of its original length. This is where the storage aspect of the device comes in, as the researchers hope to be able to delay a single photon almost permanently, resulting in a device that can store "incredible amounts of information in just a few photons": an enticing thought for a world currently satisfied with a maximum of 1TB hard drives based on physical platters. A pity then that the world is completely distracted by the potential for "Photon on photons" jokes that this throws into the ring.

[DJ @ Jan 21st 2007 4:46AM]

I can imagine endless possibilities with this technology. From communication in space to general storage in handhelds...

[Tim @ Jan 21st 2007 4:59AM]

I don't understand the physics involved. How is it possible to imprint a atom of light (a photon) with data? I would really enjoy learning about this technology...

[badgerAlum @ Jan 21st 2007 12:19PM]

Or windows for people in cities wishing to see nature landscapes. Ray Bradbury imagined this technology already, though I can't remember the title of the short story.

[Justin Eassary @ Jan 21st 2007 6:06AM]

most likely you or pretty much anybody will never understand the physics of this. i don't get it and my roommate who is about to graduate with a physics major doesn't get it. you probably have to study this specific topic for years to understand it.

[Foof @ Jan 21st 2007 6:48AM]

Part of it is getting hung up on the "single photon" terminology, which makes you think of light as existing solely as a particle. First of all, photons aren't atoms (!= proton), they're subatomic. More importantly for this application, light has this really weird physics property of existing as (or exhibiting properties of) both a particle and a wave. So perhaps a better analogy/simplification than "imprinting data onto an atom" would be something like "storing information in the diffraction patterns of a wave." By knowing how waves act, you can analyze such patterns and movements and "play the wave backwards" to determine the original shape (stencil) that formed it.

[Andy @ Jan 21st 2007 12:29PM]

particle/wave duality is a property of all fundamental particles, not just photons. Matter particles (electrons and quarks) also have this property.

[Mank @ Jan 21st 2007 7:44AM]

I think it's basically a tiny beam of light being fired through a tiny stencil, and the light that survives through the stencil is the data (like what would happen if you painted over a stencil on a sheet of paper, the paint only reaches the paper in the areas where the stencil has holes) and then the cesium gas does stuff to it which makes it be able to be used for storage.

[treetrunk @ Jan 21st 2007 9:23AM]

Mank- your explanation sounds fine on a macroscopic (ie, "big") level, but you're oversimplifying. It'd be a bit like painting over a stencil but only using one atom of paint- you can't permanently change the shape of an atom so whatever your stencil looks like you'll end up with a single spherical atom when you take it away.

But of course, as others have pointed out, it isn't like that atall on a microscopic level because of the wave-particle duality of light. I'm more engineer than physicist, but Foof's "working backwards" idea and David's "Young's slits" analogy seem plausible to me.

[David @ Jan 21st 2007 8:43AM]

While the team may have allowed only a single photon to pass through the stencil, they don't mention how they retrieved the final image shown in the article. Generally, when information is imprinted on the wave function of a photon, you can't retrieve this information from just that single photon alone. An example is the famous double-slit experiment. All physics students know that if you shine a beam of light through a pair of slits and only a screen, you obtain a series of bright and dark lines ... an interference pattern due to constructive and destructive interference of light passing through each slit. Now, if you reduce this light down to one photon at a time, it turns out that you still get this interference pattern since the wave function of even a single photon "sees" both slits. However, that single photon, when it hits the screen, doesn't create the full interference pattern. It merely creates a spot somewhere consistent with the pattern. This is because the information about the slits is carried by the photon's wave function, which describes the probability of detecting the photon in one physical location or another. For any individual. observation, you merely observe the photon in one place, consistent with this probability. You thus need to allow many photons, albeit one at a time, to continually pass through the slits and onto the screen. Over time, a pattern of dots build up that merge into the interference pattern. It's likely that the same thing applies here. One photon carries the "UR" imprint, but detection may require many of these imprinted photons. I wish the article went into more detail.

[John @ Jan 23rd 2007 6:17AM]

Hello David,
you are exactly right. Quantum mechanics is an interesting field. I suggest reading the paper as it clears up many of the issues discussed in this blog. In reality we used a stream of weak coherent pulses, which are superpositions of all possible number states of the electromagnetic field, but the probability of measuring two photons in the detector at once was about 1 part in a milliion. It did require an ensemble (a large number of identical events) of pulses to see the image. It should also be pointed out that if the image is an eigenstate of the measuring device you can determine the image in a single event. We want to work on that.

[Bob @ Jan 21st 2007 9:03AM]

Why didn't they just used photonic chirality to store binary data?, like everybody else in the galaxy. Photons are a dime a dozen googles.

[jgood @ Jan 21st 2007 9:48AM]

To any of us still trying to contemplate an easy way to make sense of this phenomenon, I'd just like to quote Shakespeare’s' Hamlet and say, "There are more things under Heaven and Earth than are dreamt of in your philosophy Horatio." What this means to me is: [1] most people are smart in one or more ways, [2] there is something new that anyone can learn, and, [3] it's often quite interesting to pursue something new. Of course, always look for a simple answer, first (Occam's razor), but there are some things that are beyond our current experience and expectations (and beyond simplistic explanations), i.e., almost mystical and fantastic. Things that gifted physicists and mathematicians would say are of incredibly beauty, I suppose. Then again, sometimes, it’s takes genius to cut through all the noise to distill something to its most basic and pure form. Anyway, having read several of the popular science books on Quantum Physics back in the day by those writer’s which try to explain such things to us mere mortals, all I can say is that I still don’t have a good handle on the key concepts, let alone the science. Nevertheless, I don’t regret having opened my mind a bit to a type of thinking that seems contrary to ordinary logic. Of course, the science hasn’t fully solidified on matters related to this post, and not every physicist is on-board with the counter-intuitive explanations (though most of them seem to be). But if practical devices can be developed using such science (such as, for example, quantum computers calculating currently intractable problems by analyzing all possible solutions simultaneously to collapse to a solution), then more power to it…at least until even better science come along. The point is, if one is interested in going for a proverbial ride down a mind-bending road, then pick up one of the many popular science books (such as one of those by Paul Davies), and strap yourself in. Just be careful that you don’t get too addicted and lose the balance. But whether we partly grasp such things or not, we’re in for an exciting century, don’t you think! And thanks to Engadget for calling such things to our attention (even if not necessarily gadget-centric), and thanks for all the interesting reader viewpoints...because, I for one, enjoy reading them.

[tadghostal @ Jan 21st 2007 10:11AM]

I think we've all overlooked the most immediate and important implication of this technology: Softer, fluffier pancakes for *all*!!!!


Woot! Go UR!!!

[Rob @ Jan 21st 2007 11:03AM]

Interesting stuff. I was going to buy a new hard drive today, but I think I'll wait for this technology to come to market. I'm sure it's right around the corner...

[Brian @ Jan 21st 2007 12:12PM]

the first thing that came to my mind was a pinhole camera - is this at all similar?

[Dave @ Jan 21st 2007 1:08PM]

I'm in ur wave function, imprinting ur photonic info.

[waruwaru @ Jan 21st 2007 2:52PM]

Now it will be easier than ever to hide your porn collections.

[Limerick @ Jan 21st 2007 5:03PM]

all UR photons are belong to us.

[justdave @ Jan 21st 2007 6:07PM]

Fair play to the evidently uber clever scientists. All our photons are belong to them, indeed.

[Sagar @ Jan 21st 2007 6:44PM]

Woot, Professor Howell taught me Physics 121 (kinematics and the sort) my freshman year.

He was always way too smart for us as he was used to teaching grad students. Awesome work anyways!

[frank @ Jan 21st 2007 8:45PM]

This is the typical researcher coming up with a sensational headline to make his research seem more important than it is. Their real accomplishment was to slow down and compress the photon before it is detected. But the image you see is made by MANY photons. Notice there is a "scanning optical fibre" which means that one or photons are detected at each position of the optical fiber and thus MANY photons are used to create that image. This is exactly what you would get if you put a lens between the source and receiver of the photons. The only way the statement about 1 photon is true is that they can turn down the intensity of the light until on average there is only 1 photon at a time in their apparatus. Exactly the same thing would happen with a lens also. So the headline is just hype. Using the Cesium vapor to slow down and compress the light is nice, but not new or newsworthy. IMHO.

[Ken @ Jan 22nd 2007 1:47PM]

This is certainly not old news. The claim of the study is indeed that they created the image with a single photon.

Mank's description is completely accurate. Single particle of light through tiny stencil. That is exactly what they did here.

I like to make annalogies of particle/wave duality to drops of water. Except, in this case, we are talking about drops of light. A drop of water is held by cohesion to a natural state of equilibrium giving it a quantum of sorts. Photons are much the same, but replace water with space-time variances.

[John @ Jan 23rd 2007 6:19AM]

hello Frank,
of course you are entitled to your opinion, but I recommend reading the paper. I didn't actually make the title to the headline, that was the publicist, nor did I write the press release. The article has a different emphasis than I would of liked, but that's okay. The cool part is not necessarily just compressing the light, because many have done this including us in several other experiments. In fact, the cool part is not putting an image onto a single photon, because we have done that before too using entangled photons. The cool aspect is that the entire transverse image is preserved in the vapor. You can think of this as wavefunction preservation or just amplitude and phase information preservation. I suggest reading the paper, maybe you will change your mind. cheers

[Graham @ Jan 22nd 2007 12:52AM]

ah, it's always great to see when an excellent (and often overlooked) university pioneers a new technology. Go dandelions! ;)

[jason @ Jan 22nd 2007 12:59AM]

It's worse than that, it's physics, Jim. . .

[Ebzy @ Jan 22nd 2007 6:27AM]

@Foof, David, Andy, and frank

Err... Yeah.

Although I think Brian explained it better

[Greg @ Jan 22nd 2007 10:26AM]

Could this be the birth of the isolinear chip?

[scott berfield @ Jan 22nd 2007 1:23PM]

I would really love to be able to even PRETEND to understand how this works...

[siapitan @ Jan 22nd 2007 9:28PM]

UR = UNDERGROUND RESISTANCE

[me duh @ Jan 23rd 2007 5:03AM]

Dayum. "A drop of water is held by cohesion to a natural state of equilibrium giving it a quantum of sorts. Photons are much the same, but replace water with space-time variances."

Thanks for that. All of a sudden i feel i have some sort of chance. And much the most intelligent thread on Engadget ever.

[JR Minkel @ Jan 24th 2007 1:58PM]

I tried to clarify how this experiment worked in a story for Scientific American's web site. Some of the commenters above are exactly right that recovering the image requires many photons, as in the double slit experiment.

Here's the link, if anyone's interested: http://www.sciam.com/article.cfm?chanID=sa003&articleID=5538BDC4-E7F2-99DF-38BA958C99BC5960

[neo researcher @ Jan 30th 2007 1:00AM]

Perhaps one of the values of this research is the imprinting onto a subatomic particle itself. Frank states this as old news: Yet another view into subatomic interactivity adds to overall insight and is a valid contribution. As JGOOD reminds us - as scientists, we are still making known the unknown. And, like with all new and interesting insights, it is too early to draw conclusions. So what.

Yes, more details would be great.