Dense Information Coding.

[swestrup]

I've just learned that University of Rochester researchers have managed to encode a 21 by 41 pixel image into a single photon of light, and were able to decode it again only slightly degraded. Its a major step forward for optical data encoding.

Comments

[sps.livejournal.com]

Is that your interpretation of the article? I couldn't make head or tail of it. Does 'pulse' = 'photon'? How is readout performed? The text seems to be about slow light, not data storage or encoding. And how is storing a couple of hundred bits in four cubic inches a density breakthrough, by any measure? That's not even very exciting for clockwork. They talk about six megapixels, as if this was something accomplished (still not in any sense clever to fit six meg in four cubic inches when you can fit eight gig on a CF card...), but then that contradicts the earlier paragraphs.

I mean, not that it sounds like they are lying, but I can't interpret anything from that blurb.

[swestrup]

LJ screwed up. My comment to your post is below.

[swestrup]

Yeah, the wording sucks, but they sent a single photon of light through a stencil, successfully encoding all 800 pixels into that one photon. Then they slowed the photon down so that they could store multiple photons in one place. Then they later sped it back up and recovered a mostly intact image.

The key point is that they did this all with a single photon, and that they never had to convert the photon to anything else in order to store it for a while. Its hoped techniques like this will make optical computing far more successful.

[sps.livejournal.com]

Well, that's clearer than the article. But what's the mutual relevance of the two things? Is the result one of encoding, or fo storing? Couldn't you do the storing with a longer, faster delay line, anyway? And how is the readut possible? They have always told us that one photon encodes as much as you want but only gives up one bit. What changed in physics?

[swestrup]

How they got the data out again is, I admit, the part I can't figure out. I shall probably see further articles on this with, hopefully, better explanations.