Paper on IR to VIS conversion, no electronics involved

[enricosavazzi]

Proof-of-concept all-optical IR to VIS conversion.

https://www.laserfocusworld.com/detectors-imaging/article/14205548/nonlinear-metasurfaces-make-enhanced-ir-imaging-possible

 

A reprint can be downloaded from Researchgate:

https://www.researchgate.net/publication/352411801_Infrared_upconversion_imaging_in_nonlinear_metasurfaces

[colinbm]

Very interesting thanks Enrico
Few people realise that green lasers are in fact IR lasers with the wavelength halved to output green light.

[Andy Perrin]

4 hours ago, colinbm said:

Few people realise that green lasers are in fact IR lasers with the wavelength halved to output green light.

Hah, I guess that depends on your sample of people. Of the people I know, probably a substantial percentage of them know that. Of the general population, almost nobody knows anything about lasers at ALL, so I guess that would be a true statement about them.

[Wayne Harridge]

Interesting indeed, I wonder if there is some way of "downsampling" UV and doubling the wavelength (halving the frequency)?

 

[Andy Perrin]

9 minutes ago, Wayne Harridge said:

Interesting indeed, I wonder if there is some way of "downsampling" UV and doubling the wavelength (halving the frequency)?

 

That's UVIVF (UV induced visible light fluorescence). We do it a lot here!

[Stefano]

Fluorescence doesn't necessarily double the wavelength. I think what he meant is if it is possible to take for example 375 nm laser light and get exactly 750 nm light from it.

[Andy Perrin]

Stefano, I think the answer is “yes” to “can you exactly double the wavelength” just by choosing appropriate fluorescent materials, to which you could add some dichroic coatings to exclude unwanted wavelengths if it was necessary for some reason. The above article is about a carefully engineered material/surface, not something they found growing naturally. You can do the same in the other direction if you wanted. 
 

The substance of my reply is still the same, UVIVF is easy, it’s the opposite direction that’s hard because it’s going uphill, from low energy to high.