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Take the array of nanoscale electron emitters developed for the SED (surface-conduction electron-emitter display) technology. But instead of overlaying a grid of phosphors, you add a grid of 'undulators', devices that cause the electrons to oscillate as they travel (as in a free-electron laser). The
oscillation can be tuned to cause the electrons to emit photons of any wavelength desirable. This means each pixel can be of ANY colour, not just a mix of 3 single-wavelength subpixels. If you wanted to be REALLY fancy, you can rapidly vary the wavelength emitted by each pixel over a wide range, so each pixel does not emit a single colour, but a SPECTRUM!
Add a method of recapturing the electrons (simple conductive-coated glass?) to prevent charge buildup, and voilà! You have now surpassed the colour accuracy of every display on the planet, including printed media and celluloid film.
Admittedly, the colour range isn't really infinite: you hit weird waveguide problems with low frequencies (around the farIR), and power input issues with short wavelengths (probably near-UV).
Free Electron Lasers
http://en.wikipedia...er?useskin=monobook
[EdZ, Oct 26 2011]
Undulator
http://en.wikipedia...or?useskin=monobook
[EdZ, Oct 26 2011]
[link]
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//The oscillation can be tuned to cause the electrons to emit photons of any wavelength desirable.// |
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Can this method modulate the phase of the photons too? |
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If two wobblers are exactly in phase with each other, are the emitted photons fully coherent? |
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I'm wondering if this could be used to display holograms. |
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// Infinite colour range display // |
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// the colour range isn't really infinite // |
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Be careful, the advertising standards regulators will come after you ... |
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// add a grid of 'wobblers', devices that cause the
electrons to oscillate as they travel (as in a free-
electron laser). The oscillation can be tuned to
cause the electrons to emit photons of any
wavelength desirable.// |
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[Wrongfellow] I believer certain magnet configurations can produce radiation with a desired polarisation.
[MaxwellBuchanan] My mistake, the correct term is 'Undulator' (the desired radiation is monochromatic, not broadband). |
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I've added some links. Because the desired light output is very small (in the microwatt range) per pixel, I'm hoping the electron beam power is similarly minimal, rather than the large accelerators used in current high-power synchrotron sources. |
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Does this really help? You're still only transmitting a single frequency at any given time. Real things reflect a spectrum of different frequencies together, not one at a time. |
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... but real eyes only contain four kinds of
photoreceptor, so you should only need four
wavelengths, corresponding to the peak absorbtion
of each, to reproduce, perfectly, any color at all. A
continuously tuneable single-line spectrum (in
clusters of 4 sub-pixels) would be
more than sufficient. Overkill, even. |
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Temporally blurred spectral emission can be done by rapidly sweeping across the spectrum. But even emitting only one wavelength per pixel would be a significant improvement over primary-subpixel displays. |
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One wavelength per pixel allows the production of any spectral colour, but not any human perceivable colour. If frequency and brightness were all that mattered, there would only be two degrees of freedom, but there are at least 4. |
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//you should only need four wavelengths, corresponding to the peak absorption of each, to reproduce, perfectly, any color at all// Not quite; reds and violets would not be represented well, as they lie outside the range of the absorption peaks. It seems possible that two emitters per pixel, each independently frequency and brightness controlled, might do. |
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//emit photons of any wavelength// Will the display carry a health warning about viewing images which display as high-energy X-rays? |
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How do you propose to construct these pixel-sized
undulators or wigglers? |
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