Holography R&D?

This is a forum to share experiences and ideas about holography.
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Martin_D

Holography R&D?

Post by Martin_D »

Hi all,

I'm currently writing a paper about holography with the main focus on new technologies and current R&D in the field of holography. Thought some of you might give me some hints? Where do you think is holography going? What are emerging technologies?

So far I've been researching into Holographic Data Storage which seemss to be out on the market pretty soon and 3D Holographic Displays which are apparently making progress as well. But what else? Anything "spectacular" on the horizon?

Thanks guys

Martin_D
Dinesh

Holography R&D?

Post by Dinesh »

Did you look into proteins as a material for holographic data storage? Bacteriorhodopsin seems to be a promising material. Briefly, the visual purple on your retina that captures light and passes it on to the brain contains various light-sensitive proteins called Rhodopsin. The different varieties of rhodopsin in visual purple code for different parts of the spectrum. Built into the rhodopsin is a mechanism to capture the visual field, pass the data to the brain and clear itself for the next visual field. Any material that can 'read', 'write' and 'erase' visual fields is clearly a good contender as a holographic memory material.
Martin_D

Holography R&D?

Post by Martin_D »

Proteins for data storage? No, didn't look into that so far. Sounds quite interesting though. Thanks Dinesh :)

But I found something on http://www.colossalstorage.net they call it "Atomic Holographic Spintronic Optical Data Storage NanoTechnology"... I haven't looked into it so far. I don't even know if it's "holographic" at all...despite the name...
Dinesh

Holography R&D?

Post by Dinesh »

Um...Let me politely say that there exists a certain group that tries to impress other people by piling one scientific term on top of another in a constant flow. Usually these words are "Quantum", "Electron", Einstein","Hologram", "Heisenberg" or "Uncertainty", "Holography", "Molecular..something". These words are connected by less-than-scientific adjectives which also sound incredibly impressive if you're a Star Trek fan. In fact, whoever wrote this would be a great script writer for Star Trek episodes.
Let's see, they claim 40 Gb/sq in from which they get 40,000 Terrabits/cc not 40,000 Gigabits, which would be 40 Tb, 40,000 Tb! Well, 40 Gb/sq in transforms to 40*(2.5^2)*(10exp3) Gb/sq cm = (approx) 210 Gb/sq cm. How they now go to a volume measurement escapes me, but we continue assuming the average density is the same. So one side of this memory now contains sq root(210) Gb/sq cm and so one gets 210*((sq root)(210)) = (approx)5000 Gb/cc, not 5000 Tb/cc. There's no such theory as the Einstein/Planck Theory of Energy Quantum Electrons. In fact, there's no such thing as "Quantum Electrons" and it was Bohr who came up with the theory of quantised electron orbits - not as impressive as Einstein or Planck perhaps! I couldn't find the word "Heisenberg" anywahere or even "Uncertainty", maybe that's old fashioned in these "Superstring" days!
Unfortunately the more this sort of this happens, the more the public is unimpressed with a real hologram.
Last edited by Dinesh on Fri Oct 14, 2005 1:03 am, edited 1 time in total.
lucaslab

Holography R&D?

Post by lucaslab »

Holography has many scientific applications. And many more practical uses. Beside what we are hearing about holographic TV, holographic storage units and holographic universe the most practical application is that the holograms are the future of photography. Maybe in the future every photograph will be a color 3d hologram. Also the definition of hologram is "a lenses system of 3d photography" as described by Denis Gabor in his Nobel award for his discovery of holography in 1971.
Martin_D

Holography R&D?

Post by Martin_D »

@dinesh:
nice calculations :) I haven't thought that far, but I guess you're right... the website looks quite confusing as well...

btw, dinesh, Lyncee Tec (http://www.lynceetec.com) is currently developing a technique called "Digital Holographic Microscopy" and they record a hologram with a CCD camera... I just mention it because on the old forum you said you could't imagine an hologram being recorded on a CCD camera due to resolution shortcomings...
Dinesh

Holography R&D?

Post by Dinesh »

I didn't get a good look so i didn't see exactly what they were doing. However, it looks there might be two things going on. Firstly, they seem to be using holographic methods in confocal imaging. This is possible. In fact I have an article by Leith who was working on this. Since the angle between 'reference' and 'object' is only a few degrees, the fringe density can be captured by a ccd. In fact Leith claims it improves confocal microscopy by improving the noise characteristics. One day I'll sit down and study the paper! In a standard hologram, the fringe density in lines/mm is given by sin(theta)/lambda. If you assume that a 0.5mmx0.5mm ccd had a resolution of 500x500, this corresponds to a fringe density of 500 l/mm assuming 2 greyscale levels. At 633nm, the angle between beams is about 20 degrees. However, with only two greyscale levels, there's be no real fringe detail and hence no real image contrast - the noise would overwhelm the image. If you assume a much more reasonable 5 greyscale levels, then the interbeam angle would need to be about 3 degrees in order to record the holographic fringes.
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