REALLY cool 532nm fluorescence (not the norm)

[Switch]

I'm pretty doubtful the IR is producing any visible effect.Though I have heard on the forum that some minerals might have some reaction to it, creating an "electron trap" IIRC. :-/ :-/ :-/

 

[Ace82]

I am curious to know... :-?

 

[MarioMaster]

fluorescence can only happen at a longer wavelength than the source (the only exception here being where the crystal itself becomes excited and lases like the YVO4 and KTP crystals, but that's not really fluorescence. Energy is lost during fluorescence so you get longer wavelengths instead of shorter, therefore any fluorescence from IR would be even deeper into the IR spectrum

 

[Ace82]

Awe, so it's simple 532 fluorescing then, probably the maximum wavelength possibility too!

 

[Dr_Evil]

Nice ring and dog.

My step-dad had a necklace made for my mom over in Afghanistan for ~$60. She took it to a jeweler to find out how much it might be worth. He said it is worth about $3k and thats without checking out the clarity and stuff for all the stones. It is made with yellow sapphires but I can't remember how many there are.

 

[pullbangdead]

I've been trying to get one of my optics professors to tell me what impurity causes it.

Well that's your problem right there, you need someone who actually knows what's inside, like a materials scientist.  Of course, they'll probably just tell you it's an oxygen vacancy.  When in doubt, it's probably always an oxygen vacancy  .  (Sorry, that's kind of a running joke with some of the theoreticians in my office.  One of them gets really mad because another one attributes any weird outcome on ZnO to the oxygen vacancy, no matter what the evidence might be.  Heck, they get so excited, sometimes they even forget and blame the oxygen vacancy for weird things in GaN, ha!  Now if only they could find that oxygen, then maybe they could find the vacancy it leaves...).  

But yeah, it might be out there in the literature, but if it isn't then it may just be that no one knows.  You could measure it to get the exact spectrum output, and then run it through a bunch of computer models to find a good guess of what impurity might cause such an emission.  You could also do some real tests (SIMS maybe?) to find the dopant levels of different dopants in there, but if it's a vacancy the dopant concentrations won't tell you anything.


And others: you can get fluorescence of a wavelength shorter than the wavelength causing the fluorescence, but it's tiny and not typically likely to be visible.  Most fluorescence is a photon knocks an electron up an energy level, and that electron (after a finite time) spontaneously falls back down to ground and emits its own photon that is characteristic of the energy band that it fell through.  Now, if an electron gets exciting up by a photon, and before it has time to spontaneously fall back down, it gets excited again by another photon, it can get knocked up another level.  Now, it's sitting 2 levels high, at what could be a higher energy than the energy of either photon that excited it there.  If it spontaneously radiatively falls back down to ground in one step, it will emit one photon, and that photon could be of a higher energy than either photon that did the exciting.  Then, the wavelength would be shorter.  That requires several key things to happen, all of which could be unlikely, resulting in it either not happening or happening so little that it's not bright enough for you to see without spectrometers and such.  So it can happen, and you might see it, but don't bet on it.  So no, you're probably not getting IR to fluoresce anything in the visible range.

 

[chopper]

fluorescence can only happen at a longer wavelength than the source (the only exception here being where the crystal itself becomes excited and lases like the YVO4 and KTP crystals, but that's not really fluorescence. Energy is lost during fluorescence so you get longer wavelengths instead of shorter, therefore any fluorescence from IR would be even deeper into the IR spectrum

Right... I should have figured that out... Mine does it a lot too, I think I'm also getting it with my blue ray. Pics to come soon.