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ArcticMyst Security by Avery

Stupidity at 808nm...

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Jan 29, 2014
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Tonight I put my goggles on and fired up a 40W 808nm FAP laser at relatively low current to do some experiments with optics, ramped the voltage up to about 16 amps of current draw and saw a bright red spot on the lens.... I thought huh? I shouldn't see anything and turned it off, looked at my goggles and had the wrong fricken ones on, only good for 532nm... SHIT.... I seem to be fine, but could have blinded myself, 16 amps probably produced several watts, the FA808 40W unit I was using begins to lase at 9 to 13 amps... Later tested my 532nm goggles with a 300mw 808nm pointer and found they block about 20 percent at 808.

Problem was I didn't check the goggles closely enough, they were both similar in design and color but marked differently, of course.
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Scary story...thanks for sharing though to remind us! If it makes you feel better, I got a glimpse of the output of a 795nm laser running at 50W a few months ago and I have no noticeable vision changes. I was wearing the right goggles, but they didn't completely cover my eyes and I saw the laser through the opening!
 

Pman

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Didn't do this with IR but I bet I'm not the only one who accidentally put the wrong goggles on for red/green/blue. Awful easy to get bitten when you are thinking about other things. Have to remind yourself to never get too comfortable with them. Too many easy mistakes like # of cells and polarity.
Glad your OK;)
 
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Never seen IR goggles before, so can't speak for that wavelength, but some general tips that will make this sort of mistake almost impossible.

1.
Have the goggles in a case clearly labelled with the wavelength range, and a plain English description (Laser Protection 190-540nm - blocks BLUE/GREEN)

2. (Not a precaution, but a rule of thumb)
The coating of the goggles should NOT match the colour of the wavelength it is protecting against. If you're glasses are green, don't fire up the green laser

3.
Have familiar coloured objects in your workspace, like if you can see green leaves, or red apples, you know you are wearing the wrong glasses for your green and red laser respectively.

These to some may seem overboard, but as your example demonstrates, mistakes can be made, and people forget glasses are only protective equipment, not protection, and complacency can result. Because of the immaterial nature of optical hazards, people forget this, like just because you are wearing a helmet does not mean you are 'protected' from crashing your bike into a wall, it just mitigates the consequences.
 
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Sep 20, 2014
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Yikes, that's a powerful laser! Glad you've still got both eyes...
 
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WOW, could have been tragic!! Hope that you are okay.
Several months ago a friend bought several lasers at once(these were their first lasers)
They all were around 200mW each. The goggles were not marked so they thought the red goggles went with the red laser. Needless to say I freaked when I came in the room and saw that. I read them the riot act and then sat down with them and taught them as much as I could. Nothing like knowledge BEFORE you attempt something new.
I know you are not new to this but we are all human and make mistakes. Thanks for sharing as it will make all of us more aware of that pitfall.
 
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Whew glad you didn't have an accident. I guess you can never be too careful especially with lasers.
 

Teej

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Was the spot you saw from the dot ON the glasses, or, were you looking at a dot on something a ways away from you?

Cataracts would be the primary concern for that wavelength...which may take a while to develop if you really got a direct hit.

The glasses at least tend to spread the dot out a bit, rather than send it in undistorted, so, lets hope that whatever combo you were hit with was dissipated enough to do no damage.
 
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the eyes are relatively tolerant of 808 and alot of NIR, just looking at the emitters in a side-long manner generally wont cause an issue I've found, so long as you're not staring at them or something. (or into the beam obviously) UV is far less forgiving. Definitely a lesson learned though here, never hurts to double check. I have a pair of YAG protection glasses for lamp pumped Nd:yag/vanadate and ti:sapph lasers. works great for all that NIR and its doubled stuff too. its like OD7 or 5+ for most all those ranges. so usually they're what i turn to unless i'm working with red or something.
 
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I was trying to line up the output of a 50W FAP808nm laser, but I had only turned the current up to a max of 13 amps so it wasn't putting out full power, perhaps a few watts. I was using my iPhone camera to look at the laser while trying to align it most of the time, then got a glimpse of the beam directly on accident and saw the cherry red spot reflecting off of the input of the beam expander. Even with goggles on, I use my camera to see the beam, otherwise it is invisible with the proper goggles, what surprised me was the ability to see the red dot with the goggles on, I knew immediately something was wrong, the proper goggles won't allow you to see a hint of red.
 
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You might still see red depending on what the output is. I can see a little red on 808 pump diodes below 250mW. Just don't look at it directly.
 




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