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ArcticMyst Security by Avery

Nanocups Produce Frequency Doubling

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Aug 3, 2011
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Tilting 'nanocups' double optical frequencies - physicsworld.com

A new type of structure for converting red light into blue has been unveiled by researchers in the US. Known as frequency doubling or second-harmonic generation (SHG), the conversion involves "nanocups", which are tiny, artificially designed 3D structures [...] researchers believe that the new structures could be adapted to achieve frequency doubling in parts of the electromagnetic spectrum where it is currently not possible.

SHG is a nonlinear optical process whereby two similar photons are converted into a single photon with twice the energy – and therefore twice the frequency or half the wavelength – of the initial photons. The process was first demonstrated in 1961 when researchers focused a ruby laser with a wavelength of 694 nm into a quartz sample and observed that the light that was subsequently emitted had a wavelength of 347 nm.

I think this technology could drastically improve our existing range of colors and the power we can get out of some of them.
 





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Aug 15, 2009
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It involves nanostructures, so it will be a very long time until that becomes anywhere near mainstream. Also, there are many fantastical nanoscale phenomena claiming wild thing, I'd wait and see.
But in theory SHG works better at material interfaces because that makes quite a non-centrosymmetric medium which is needed.
neutrinos.png
 
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So the first published result was 50 years ago and you think that it is relevant now because....
Not to be mean but with the speed of scientific progress in all fields you think that maybe something more would have come from this in the last 50 years.
And I notice that the article here doesn't mention input power versus output. Nor do they make mention of how difficult the process was to produce or it's replication.
Limits on just what frequencies can be made to do this and WHY they don't work with others. How much interference the process induces or if the process was destructive to the medium when done...
So many unanswered questions.
And 50 years to come up with them.
Still nothing.

Doesn't look too promising unless there are a bunch of associated discoveries that aren't being included.
Just my take on it though.

You are welcome to your own opinion.
 
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let me make it clear:

the new structures could be adapted to achieve frequency doubling in parts of the electromagnetic spectrum where it is currently not possible.

This means the technology if adapted beyond the R&D range, will increase our access to otherwise obscure laser colors.
 
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Well it could mean in the visible light range of the electromagnetic spectrum, as small a part as that is. But there is a whole lot more to the spectrum that is far below and above the human eye perceptable portion.
I think that there would be far more interest in those other portions than the limited visible portion that is already saturated with options.
Think about using a laser light source and frequency multiplying to produce microwaves. The military might be interested in using a light powered microwave weapon or some variant for data transmission. Or using cheap easily produced infared to create higher level waves and signals. Who knows.

Not that I'm saying that it can't or won't !
I'm just looking a bit more at a bigger picture.
Who would fund the R&D ? How long would they be willing to wait for results ?
All those kinds of questions.

It would be nice to see something new and cheap enough to get, but I'm not going to hold my breath.
:p
 

Benm

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It may take a long time before we see practical application, but the most interesting part isnt really answered by the article:

What does it require from the pump light?

The limitations of frequency doubling at the moment are largely there because the pump light needs to be a very narrow spectrum, and can only be produced by a laser. This gives us 1064 and 946 do double to 532 and 473. There is no reason the nonlinear crystals cannot 'make' an output of 500 nm, as long as you had a 1000 nm solid state laser to pump them.
 
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Great... We now have the first component to a time machine; a negative refractive index nonlinear optical medium.
 




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