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ArcticMyst Security by Avery

Concerned about IR emissions from a Rayfoss laser

DH1

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Apr 29, 2010
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I was quite pleased with the 100mw 532nm laser I ordered from Rayfoss that came a few days ago but now I'm quite worried. I saw a youtube video about IR emissions from green lasers and the pictures taken with my handycam are quite worrying, the image on the right of the first picture is with nightshot on and it looks like there's quite a lot of infrared coming from the laser.

Incidentally, the safety glasses are from dragonlaser and I found that they completely stopped the visible part of the beam from the laser when it was shone through them, contrary to what was said here:
http://laserpointerforums.com/f53/careful-dragonlaser-goggles-47768.html
 

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AndyR

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Have you tried taking a nightshot picture with IR dot at a farther distance? If it remains fairly well collimated, then it shouldn't be a worry considering the green will be a bigger danger.
 

DH1

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Have you tried taking a nightshot picture with IR dot at a farther distance? If it remains fairly well collimated, then it shouldn't be a worry considering the green will be a bigger danger.

At 3m the IR dot is slightly larger than the visible dot. Doesn't this mean that, when wearing safety glasses, I could be potentially shining a powerful IR beam into my eyes and not be aware of it?
 
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Thats pretty much exactly what it means, if you were to take a hit to the eye your glasses wouldn't do much because the IR would go right through. I suggest you get a cheap IR filter and fix it inside or to the front of your laser.
 

Benm

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Do you have any quantitative information on the IR? It may seem like a lot on a handycam in nightshot mode, but that doesnt give much information on how much power actually is in the IR.

As far as eye protection goes: If working with 532 lasers, go for something that blocks both 532 and IR. Goggles that only block the green but pass the IR may actually put you at increased risk, since it can be quite comfortable to look at the green wearing those, while the IR goes on entering your eyes at full blast.

Its really deceptive - half a watt of 808 nm can appear less bright than even 1 mw of 650 nm red, but do as much damage as half a watt of any visible wavelength, without the instant pain and blink reflex.
 
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I find it really weird the IR is so well collimated.It seems too tight to be the 808nm pump.I would guess it is the 1064, in which case it could be even stronger than it looks on the camera.I am not familiar enough with the topology of that laser to say for certain, but the pump being a diode and further away from the lens if it was vertical(not side pumped) would tend to make any 808 dot pretty big fast.The 1064 on the other hand would be out of collimation only from the difference in refraction in the lense material due to the wavelength difference.
I would put a filter on it.
Can any one on the forum test one of these at all 3 wavelengths?
It would be interesting to see the breakdown between 1064, 808, and 532.
 
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The 808nm pump diode usually isn't a collimated beam and will spread out. It may take quite a distance to really spread out, but That's just a guess. The 1064nm is just like the 532nm passing through the beam expander and will stay collimated. Lenses usually do have a different focal length for 532nm and 1064nm, but for a beam expander this compensates eachother mostly.
 
Joined
Nov 21, 2009
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The 808nm pump diode usually isn't a collimated beam and will spread out. It may take quite a distance to really spread out, but That's just a guess. The 1064nm is just like the 532nm passing through the beam expander and will stay collimated. Lenses usually do have a different focal length for 532nm and 1064nm, but for a beam expander this compensates eachother mostly.

I agree.And I wonder what the conversion efficiency in the KTP crystal is.EI: how much is the 1064 IR as a output percentage.A good filter and a power meter would answer that, disregarding 808 spill.
I wonder if anyone on the board has bandpass filters for 808 and 1064.That could make for a cool review.
I find the omission of a IR filter unconscionable.Do they do it just to save money, or is the additional burning power from the IR a sales ploy as well as cheaper to make?
 




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