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How much IR from 532nm before finger gets really hot

Blaster

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I have a few greens LPM at 125 mW ish but I'm curious as to approx how much power in IR they are putting out, in particular does anyone have a ball park figure on how much IR you need at very close range before your finger starts to get most uncomfortable with the heat from the IR i don't believe 125mW of pure green is enough to generate enough to real-time burn or even get close to burning ones finger from 1 cm in front of the beam as my finger is not black and just translucent to the beam so most reflects off, i may be wrong please any ideas cheers
 
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hwang21

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I think 125mW is enough to sting your skin... you can pick up an IR filter for a few bucks off of eBay, or take apart an old camera. Good luck
 
Livinloud

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ive found that the cheap IR filters on fleabay are not of good quality and vary greatly from filter to filter. i am currently tracking down a good IR filter and have a few leads but will let you know how they pan out
 
hwang21

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I'm interested, I picked up a decent one from eBay but I still would like to know what you find :beer: good luck
 
Eudaimonium

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You're hardly going to get any heat from IR on your skin. Two reasons:

1) Your skin barely absorbs that color,
2) I mentioned like, a trillion billion thousand times, IR from greens hardly poses any danger because,

  • It's not collimated, not well at least. It starts of as wide as aperture will allow and diverges abnormally - comparable to DPSS module with expander left, but final collimater removed
  • It's a lot less power than you might think. IIRC General consensus is that infrared leakage in DPSS output is approx 20% of total output, at worst.
To conclude, if your "125mW" green does not even sting your skin, it's not even 50mW, and if even 10mW of that is IR, it poses no danger what so ever, unless you are to cram the laser pen into your eye socket, but at that point you got larger problems to worry about, such as a laser pen crammed into your eye socket.


So have a nice, safe day :)
 
DashApple

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My 60W Co2 laser feels like the sun on a sunny day on my hand , warm ( large beam area ) :D
 
Eudaimonium

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ionlaser555 said:
My 60W Co2 laser feels like the sun on a sunny day on my hand , warm ( large beam area ) :D
Click to expand...

Yeah but comparing 808nm to CO2 is like comparing 405nm to... CO2 :D

Difference in waveleght is so large that CO2 isn't even "light" anymore, at 10600 nm, it's some 9800 nm outside of our visible range's IR border. Putting that into perspective, out entire visible spectrum from some 400 to 900 nm is like what, 5.1% of the spectrum of difference between IR's border and CO2's wavelenght?

Not sure why it's called a "laser" since it's just some exotic wavelenght of electromagnetic waves.

Hope I got everything correct.
 
DashApple

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Eudaimonium said:
Yeah but comparing 808nm to CO2 is like comparing 405nm to... CO2 :D

Difference in waveleght is so large that CO2 isn't even "light" anymore, at 10600 nm, it's some 9800 nm outside of our visible range's IR border. Putting that into perspective, out entire visible spectrum from some 400 to 900 nm is like what, 5.1% of the spectrum of difference between IR's border and CO2's wavelenght?

Not sure why it's called a "laser" since it's just some exotic wavelenght of electromagnetic waves.

Hope I got everything correct.
Click to expand...

Thinking about it 808nm compared to 10600 wasn't a good comparison

* Thinks before posting next time * :D
 
Blaster

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Eudaimonium said:
You're hardly going to get any heat from IR on your skin. Two reasons:

1) Your skin barely absorbs that color,
2) I mentioned like, a trillion billion thousand times, IR from greens hardly poses any danger because,

  • It's not collimated, not well at least. It starts of as wide as aperture will allow and diverges abnormally - comparable to DPSS module with expander left, but final collimater removed
  • It's a lot less power than you might think. IIRC General consensus is that infrared leakage in DPSS output is approx 20% of total output, at worst.
To conclude, if your "125mW" green does not even sting your skin, it's not even 50mW, and if even 10mW of that is IR, it poses no danger what so ever, unless you are to cram the laser pen into your eye socket, but at that point you got larger problems to worry about, such as a laser pen crammed into your eye socket.


So have a nice, safe day :)[/QUOTE
Oh it does sting my skin no doubt i used my LPM to confirm output power i just wanted a ball park figure on how much IR is likely to be in that
Click to expand...
 
Kookapeli

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Eudaimonium said:
To conclude, if your "125mW" green does not even sting your skin, it's not even 50mW, and if even 10mW of that is IR, it poses no danger what so ever, unless you are to cram the laser pen into your eye socket, but at that point you got larger problems to worry about, such as a laser pen crammed into your eye socket.


So have a nice, safe day :)
Click to expand...

I just did a little wee :p:crackup:
 
Blaster

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Cyparagon said:
That's from the green. If you're looking for a ratio of green to IR, burning your finger is not a very accurate way to determine that.
Click to expand...

That's what I'm trying to find out approximately how much IR comes out of a dpss green 125mW laser

:lasergun:
 
dubious speculation

dubious speculation

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you can hardly approximate this because it will vary between each laser, good way to test IR is to get your 532nm goggles and put them in front of the laser, then measure the laser while the goggles are in front of the beam, that way the 532nm is blocked (mostly) and only the IR will hit the LPM, the reading will tell you approximately how much IR is coming out of it

cheers, will :beer:
 
Eudaimonium

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will manners said:
you can hardly approximate this because it will vary between each laser, good way to test IR is to get your 532nm goggles and put them in front of the laser, then measure the laser while the goggles are in front of the beam, that way the 532nm is blocked (mostly) and only the IR will hit the LPM, the reading will tell you approximately how much IR is coming out of it

cheers, will :beer:
Click to expand...

If it's only "mostly" blocked, you need new goggles :D

Blaster said:
That's what I'm trying to find out approximately how much IR comes out of a dpss green 125mW laser
Click to expand...

OK to shorten the story,
Aprox~ 20-25mW out of that 125mW is IR.
 
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Blaster

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so about 20% as ball park that's great i don't think it has a filter it stings alright i just wanted to know approx the IR coming out as i don't have IR googles? Just red and Blue and orange ones thanks
 
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