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808nm laser visibility

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zamane

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My 1000mW 808nm IR laser has a slightly visible (red) rectangular-shaped output. The specs of the laser says that the wavelength is 808 nm +/- 3 nm. Isn't 808nm way above visibility range?
 





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Not way above, only a little above.. That's why we can see that dim red output. What this is is residual output that is in the visible part of the spectrum. Laser diodes are not as monochromatic (single-wavelength) as other types of lasers, and they emit across a slightly broader spectrum. The lower fringes of the 808nm diode's emission spectrum are within the visible part of the EM spectrum.. This is also the case with 780nm CD diodes.
 
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zamane said:
My 1000mW 808nm IR laser has a slightly visible (red) rectangular-shaped output. The specs of the laser says that the wavelength is 808 nm +/- 3 nm. Isn't 808nm way above visibility range?
Yes you can barely see 808nm, but YOU NEED TO BE WEARING GOGGLES! YOU CAN'T SEE THE DOT ANYWAY!
 

zamane

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Jimmymcjimthejim said:
[quote author=zamane link=1238007107/0#0 date=1238007107]My 1000mW 808nm IR laser has a slightly visible (red) rectangular-shaped output. The specs of the laser says that the wavelength is 808 nm +/- 3 nm. Isn't 808nm way above visibility range?
Yes you can barely see 808nm, but YOU NEED TO BE WEARING GOGGLES! YOU CAN'T SEE THE DOT ANYWAY![/quote]

Do you mean that I need to wear goggles for eye protection ?
 
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zamane said:
[quote author=Jimmymcjimthejim link=1238007107/0#2 date=1238015948][quote author=zamane link=1238007107/0#0 date=1238007107]My 1000mW 808nm IR laser has a slightly visible (red) rectangular-shaped output. The specs of the laser says that the wavelength is 808 nm +/- 3 nm. Isn't 808nm way above visibility range?
Yes you can barely see 808nm, but YOU NEED TO BE WEARING GOGGLES! YOU CAN'T SEE THE DOT ANYWAY![/quote]

[highlight]Do you mean that I need to wear goggles for eye protection ?[/highlight]
[/quote]
Duhhh....  :eek:  Yeah.....

Just because you can't see it... doesn't mean it won't blind you... :'(


Jerry
 
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Ruin your eyes much?
Imagine 1W of green, how bright that would be. Yeah, that's how much power you're stating at. Take care.
 
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zamane said:
[quote author=Jimmymcjimthejim link=1238007107/0#2 date=1238015948][quote author=zamane link=1238007107/0#0 date=1238007107]My 1000mW 808nm IR laser has a slightly visible (red) rectangular-shaped output. The specs of the laser says that the wavelength is 808 nm +/- 3 nm. Isn't 808nm way above visibility range?
Yes you can barely see 808nm, but YOU NEED TO BE WEARING GOGGLES! YOU CAN'T SEE THE DOT ANYWAY![/quote]

Do you mean that I need to wear goggles for eye protection ?
[/quote]

Yes.
If you accidentally get hit in the eye, your cornea will be toast.

The human eye sensetivity drops off at closer to 850nm so you will still be able to see 808nm. A 980nm laser diode should have a completely invisible output.
It's pretty trippy to [not] see an invisible beam of light slice through all kinds of stuffs.
 
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Yeah you can see 808nm, it's a deep ruby red color. It isn't the spontaneous emission of the diode, it IS 808nm, The only reason you see it is because the power level is very high.

I wouldn't make a habit of looking at it though, as seeing the dot is like looking directly at the emitter of a bright LED flashlight at close range, and just as damaging to your eyes.

A direct glance into the "weak" looking beam will blind you instantly.

Be careful... :-/
 

zamane

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Thanks to everybody for the heads up about the googles, but now I am confused. Am I supposed to wear goggles even when I am not looking directly into the laser beam (which of course I never do)? Does the reflection of 1W 808nm beam off a non-mirror surface like a wall or something still dangerous enough to necessitate goggles? I would assume that if the beam is for example directed to a dark surface , there won't be much of a reflection anyway so no danger at all.
 
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Even a black surface may reflect around 5-10% of light. It will mostly be scattered reflection, but still.... even 1% of 1W, i.e. 10mW, reaching your eyes aren't exactly healthy. For comparison, if you stare directly at the noonday sun in a clear deep blue sky, then ~2mW will reach your eye...

The danger of IR radiation is that you can't see it, so you won't look away until possibly far too late. The 808nm wavelength is just barely visible, increasing the temptation to look closer and longer...
 

Shooey

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pierce said:
If you accidentally get hit in the eye, your cornea will be toast.


So even if you just swiped it by your eye it can mess them up? (I'm way new to lasers, so gimme a break).
 
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Shooey said:
[quote author=pierce link=1238007107/0#6 date=1238018742]
If you accidentally get hit in the eye, your cornea will be toast.


So even if you just swiped it by your eye it can mess them up? (I'm way new to lasers, so gimme a break).[/quote]

Yes, these lasers will burn your eyes much faster then you can blink. ;)

--hydro15
 
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zamane said:
Thanks to everybody for the heads up about the googles, but now I am confused. Am I supposed to wear goggles even when I am not looking directly into the laser beam (which of course I never do)? Does the reflection of 1W 808nm beam off a non-mirror surface like a wall or something still dangerous enough to necessitate goggles? I would assume that if the beam is for example directed to a dark surface , there won't be much of a reflection anyway so no danger at all.


As a good measure of safety its always good to say that whenever playing with 808 you should wear goggles, no matter what the surface.

Realistically if you are VERY careful and never look at the spot within one or two feet you'll be ok. BUT you're probably never looking at the dot further away than a foot or two because the goal is to burn stuff (i'm guessing) SO, just wear the goggles :cool:
 
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Frankly, just looking at the dot from 1/10th of a watt is enough to make it hard to look at. I can't even imagine a full watt. Just because you can't see it doesn't mean it isn't frying your eyes. They use IR to cut metal (although not 808).
 

Rebel

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You are REALLY going to want goggles . You are using a class IV laser. The warning label should say something along the lines of " Avoid exposure to direct or scattered radiation ". It only says this because you can sustain irreversible eye damage from just looking at the dot never mind receiving a direct exposure.

Take special care with lasers as powerful as that one.

Happy lasing.

-Gabe-
 

honeyx

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Not way above, only a little above.. That's why we can see that dim red output. What this is is residual output that is in the visible part of the spectrum. Laser diodes are not as monochromatic (single-wavelength) as other types of lasers, and they emit across a slightly broader spectrum. The lower fringes of the 808nm diode's emission spectrum are within the visible part of the EM spectrum.. This is also the case with 780nm CD diodes.

Exactly. You can´t see IR. Only the spikes in the visible part of the spectrum. But there a lot of people here beliving you can. Claiming they can see IR and giving you a bad reputation if you dissagre rather than google a bit and to admit they were wrong.
 
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