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What exactly is "IR"?

L4sers

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Is it smoke? Like say I was shining a 30mW laser at a wall or something, and IR was released (say no filter on this laser), what exactly happens? Does "IR" get into the air? Or does the light turn into IR and if you shine it into your eyes it will blind you? Im not understanding what IR really is...
 

styropyro

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IR is infrared light. It is just invisible light, thats why so many people freak out about it. IR is just like any other light except it's invisible so where ever you point the laser, that's where the IR will be. As long as you don't point the laser in your eyes you should be fine.
 

L4sers

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styropyro said:
IR is infrared light. It is just invisible light, thats why so many people freak out about it. IR is just like any other light except it's invisible so where ever you point the laser, that's where the IR will be. As long as you don't point the laser in your eyes you should be fine.
Can the "IR" evaporate? What if I point it in like an open environment (outside like near a grassfield, a parking lot, the beach, etc...)

^^ that image makes no sense
 
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IR can diverge - and usually does - I think that's what you mean by "evaporate". Usually IR laser light diverges (spreads out like a flashlight beam over a long distance) quite a bit - if you're pointing a laser at a distant target the IR beam will spread out so much that it would be harmless, but that depends on the power of the laser.
 

styropyro

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L4sers said:
[quote author=styropyro link=1211857843/0#1 date=1211858255]IR is infrared light. It is just invisible light, thats why so many people freak out about it. IR is just like any other light except it's invisible so where ever you point the laser, that's where the IR will be. As long as you don't point the laser in your eyes you should be fine.
Can the "IR" evaporate? What if I point it in like an open environment (outside like near a grassfield, a parking lot, the beach, etc...)

^^ that image makes no sense[/quote]
Sorry but I don't know what you mean by evaporate. The IR light is near exactly like regular light except its invisible, so that means the IR goes wherever you point the laser. If you don't point the laser in your eye the IR won't get in your eyes. If you point the laser at a tree 10 feet away none of the IR will affect you. If you point the laser in a mirror than the IR will get in your eyes, but if the laser hits your eyes you have more things to worry about than a little IR leakage!
 

Razako

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styropyro said:
[quote author=L4sers link=1211857843/0#3 date=1211859430][quote author=styropyro link=1211857843/0#1 date=1211858255]IR is infrared light. It is just invisible light, thats why so many people freak out about it. IR is just like any other light except it's invisible so where ever you point the laser, that's where the IR will be. As long as you don't point the laser in your eyes you should be fine.
Can the "IR" evaporate? What if I point it in like an open environment (outside like near a grassfield, a parking lot, the beach, etc...)

^^ that image makes no sense[/quote]
Sorry but I don't know what you mean by evaporate. The IR light is near exactly like regular light except its invisible, so that means the IR goes wherever you point the laser. If you don't point the laser in your eye the IR won't get in your eyes. If you point the laser at a tree 10 feet away none of the IR will affect you. If you point the laser in a mirror than the IR will get in your eyes, but if the laser hits your eyes you have more things to worry about than a little IR leakage![/quote]
^this is true. Just be careful with the laser and you don't need to worry too much about the IR.
 

GooeyGus

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Our eyes can only see certain wavelengths of light. These wavelengths are the colors in the rainbow. BUT there are colors beyond this rainbow that exist, just our eyes cannot see them. these invisible colors are known as UV (ultraviolet) or IR (infrared).

Imagine you are trying to look at the flu virus that is on someones skin. If you could see it all over, it wouldn't be as dangerous because you know its there. But, our eyes cant see the virus because its too small. Much like our eyes cannot see IR or UV because the wavelength is too short or too long. So, to sum it all up.... Imagine if the sun was invisible but put out the same amount of light. You could stare at it, never knowing how bright and damaging it is because you simply couldn't see it.

I hope I didn't just confuse you more ;D
 

Switch

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This thread needs a quick crash course in how light and eyes work.He's asking if IR will evaporate, which to me is pretty clear that he doesn't understand how light and eyes work.
Someone needs to explain how light is composed of photons.Photons are tiny made-up particles that light is made out of.Photons travel in waves.The waves have lengths, they can be shorter or longer.The color of the light depends of the lengths of the wave(wavelength, duh) that the photons travel in.We measure wavelengths in nanometers(nm).A nanometer is equal to 0.000000001 meters, which is very very small.
Our eyes can see photons(light) with wavelengths between about 400nm(which is a very dim violet) and about 790nm(which is a very dim and dark red). For instance 532nm is the wavelength that our green lasers produce.It's between 400nm and 790nm and it's green.Now anything below 400nm(which is violet in colour) is called ultraviolet(UV) meaning beyond violet.Anything above 790nm(which is red) is called infrared(IR) meaning beyond red.So IR behaves just like any other colour of light, it's just that our eyes can pick it up.It doesn't evaporate, it travels at the speed of light , reflects off mirrors, etc...

Ok so now, here's how a green laser works and why it's good to have an IR filter:
Green lasers don't use green diodes, instead they use an infrared diode(which is a diode that emits infrared light, 808nm wavelength to be exact) and a process called DPSS to make this infrared light turn into green light.Here's how DPSS works:

IR diode ---emits IR(808nm)---> crystal ---changes 808nm to 1064nm--->another crystal ----changes 1064nm to 532nm--->

BUT some of the 808nm doesn't get converted to 1064nm , and some of the 1064nm doesn't get converted to 532nm and it just escapes the laser's aperture along with the 532nm light.This is what we call "IR leaking". An IR filter simply blocks the IR letting only the green out, so you have a pure green beam of laser light and no IR.

Does that make any sense? :-/
 

L4sers

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GooeyGus said:
Our eyes can only see certain wavelengths of light. These wavelengths are the colors in the rainbow. BUT there are colors beyond this rainbow that exist, just our eyes cannot see them. these invisible colors are known as UV (ultraviolet) or IR (infrared).

Imagine you are trying to look at the flu virus that is on someones skin. If you could see it all over, it wouldn't be as dangerous because you know its there. But, our eyes cant see the virus because its too small. Much like our eyes cannot see IR or UV because the wavelength is too short or too long. So, to sum it all up.... Imagine if the sun was invisible but put out the same amount of light. You could stare at it, never knowing how bright and damaging it is because you simply couldn't see it.

I hope I didn't just confuse you more  ;D
thanks for this! really helped!!

And thanks Switch for that very in-depth response.
 
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L4sers said:
[quote author=styropyro link=1211857843/0#1 date=1211858255]IR is infrared light. It is just invisible light, thats why so many people freak out about it. IR is just like any other light except it's invisible so where ever you point the laser, that's where the IR will be. As long as you don't point the laser in your eyes you should be fine.
Can the "IR" evaporate? What if I point it in like an open environment (outside like near a grass field, a parking lot, the beach, etc...)

^^ that image makes no sense[/quote]

No, the IR leaking out has horrible divergence. Think of IR as a HUGE invisible cone coming out of your laser. The beam starts out small and gets exponentially bigger.

The best way i can describe this is like thin ice. Think about it, if you stood up on top of thin ice, your gonna go straight through it. But if you lay down on it, your spreading your weight in a larger area. You will weigh the same amount but its just dispersed out so you don't go through the ice. So from 50 feet away, the concentration of IR is so small that it is basically harmless. But don't forget, the green laser is still there :D

here's an example picture
 

Switch

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There it goes again. Another one of those diagrams ::) I don't know if some of them actually diverge like that, but my tests, and other members pictures and videos with IR pass filters show otherwise.Seriously, it's probably 5-6mRad not 20Rad like that..... :-/
 




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