photon energy conversion 1

[smmcgee]

How is infrared light (1mm - 400nm) amplified to visible light (750nm - 400nm)? Does it require a "powered" device or is their a "material" that can do the same thing?

What device/material could be used to attenuate visible light to make it infrared?

Thanks in advance,
-smmcgee

 

[nbucska]

The energy of the photon is proportional with the frequency
i.e. you need a powered device to IR--->visible conversion.

To convert visible ---> IR you could use some fluorescent
paint if there were any developed.


<nbucska@pcperipherals.com>

 

[peebee]

You might try glow-in-the-dark toys, paint, etc. IR photon quantum energy levels might be close enough for them to glow after being exposed to IR. Just a guess.

Otherwise, as nbucska mentions, there might be phospors that would work. This would be similar to a fluorescent light, which converts UV to visible.

Seems to met that in general, UV-->visible or visible-->IR would be easier than going the other way. If I remember correctly, the higher frequency photons have more energy than low freq. So for example with UV--> visible, you get a big electron jump in the phosphor when the UV hits it, and then multiple smaller jumps back when the electron collapses back into its normal state. The smaller reverse jumps are where you get the visible light. It would be harder to go the other way, to take low-energy photons and try to change them into hi-energy photons.

Please realize this is all guesswork based on what I remember from undergrad work about 15 years ago. . . .

 

[peebee]

We all should have done some Googling first.

From a Google search on &quot;IR UV visible phosphors&quot;, the very first link that pops up is

http://www.phosphor-technology.com/iruv.htm

, from which I take the following quote: &quot;Other phosphors with emission in the UV and IR regions and even with excitation in the IR region have also been introduced. . . . Materials which can be excited with IR radiation to emit radiation of a higher energy in the IR or visible region of the spectrum are known as 'Anti-Stokes' or 'up-conversion' phosphors.&quot;

Unfortunately, it also goes on to say, &quot;Since stable Anti-Stokes Phosphors are not generally available and are difficult to manufacture, they are attractive candidates for security applications.&quot;

That should give you plenty of additional keywords to keep you busy researching this on your own for a while. . . .

 

[nbucska]

Thanks Peebee : here is a star !

<nbucska@pcperipherals.com>

 

[SolDirJoe]

Depends what you want to do I guess, but if you need only to detect the presence and level of IR striking a given surface, then a crude [powered] convertor would be to couple a basic photo-transister to a basic transistor amplifier feeding an ordinary flashlamp bulb.

The higher the level of IR, the brighter the lamp will glow. And vice versa, goint the other way.

A glass pyramid could be used to 'filter' white light by refraction, but the level of IR would low,and depend upon the type and source of white light.