Is there any threat from a Violet Class 3 laser pointer?

Hey all, this seems the place to be for guidance on laser pointers, and having recently acquired two of the things I'll be needing some explainations that aren't corporate jargon or legislation waffle.

Okay, here we go with my question.

I have two laser pointers, one is a small green beamed hand held laser pointer that runs on a 3.6volt battery and the only text on it is 'XX-850' (Which I don't have a clue as to what it means) I don't rightly know what the milowattage is on it either (as it was bought off a friend) but the beam's distance is pretty far and I can hazard an educated guess at it being a 50mw laser.

However, my question does not concern this model, in fact I may get rid of that one. My question is regarding my other laser pointer:

A 405nm, Class 3 laser pointer with a beam of <5mw. It has a violet beam which sometimes turns blue if directed at a flourescent surface. Now, my question is, how safe is this model? Out of the two I would have guessed the violet pointer would be safer due to its lesser milowattage but on reading up about the violet laser I found something about Ultra violet emissions sometimes occuring. I want to know what, if any, are the risks of these possible ultra violet emissions (hopefully in the form of exposure rates and risk percentages) and any harmful side effects, as we all know, ultra violet rays are not something to be trifled with. And, as a man who only got the laser pointer as a safety tool I don't like the idea that it can harm me somehow with me not knowing about it.

My main concern is regarding the UV stuff, I full well know the rudimentary basics, I'm not talking about "how long can I shine the thing in my eyes for?" I'm speaking in terms of underlying harm, the notion of radiation poisioning does not sit well with me.

If an individual(s) well schooled and experienced with such things can put my mind at rest about the issue I'd be most grateful about it.

Many thanks to you.

Hmm...im not realy experienced with such things but i have read alot about lasers in the last 4 weeks and i've never read anything about UV emissions. The only "unwanted" emissions i read of are IR (infrared) emissions which occur when an DPSS (Diode Pumped Solid State) Laser didn't have an appropriate IR-Filter installed. These emissions could come out of your green pointer.
The violet is as far as i know a diode without "unwanted" emissions..
Hopefully this answers your question and hopefully i'm right on my guesses!?

btw.: It is milliwatt not milowatt..0o

regalis said:

btw.: It is milliwatt not milowatt..0o

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It's a _MELLOW_watt dude!

If your 405nm laser really is <5mW, you have nothing to worry about.
Even with a more powerful 405nm laser, you don't have to worry about UV, because the 405nm laser is really near-UV, it's in the "visible" part of UV. Just don't shine it into your eyes (or reflect it off of a mirror into your eyes) and you should be fine.

Ash said:

If your 405nm laser really is <5mW, you have nothing to worry about.
Even with a more powerful 405nm laser, you don't have to worry about UV, because the 405nm laser is really near-UV, it's in the "visible" part of UV. Just don't shine it into your eyes (or reflect it off of a mirror into your eyes) and you should be fine.

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Great, good to know.

Also, thanks for the correction on milliwatt. I'm actually a grammar nazi when it comes to forums but I've only heard the term spoken (and only recently) aloud so was pretty much going with a phonological spelling.

Yeah my laser is <5mw it says so on the model itself, unless it's lying to me...
so I think that's all I may ask around here since I'm not into customization or builds so many thanks again for your help everybody!

The labels don't mean much you need a laser power meter to know for sure. I wouldn't worry about it too much just play it safe and keep it out of your eyes.

Don't assume it is less than 5 mw because of the label. A lot of chinese companies put that on there to slip it past customs. if you can focus it and ignite a match or burn your skin you are way over 5mw. even if you can't, it doesnt mean that are still safe. the only real way to know is to have it metered. maybe a reputable member lives close to you.

also as to your UV concerns... as ASH said it is near UV. and known UV problems/effects happen around 350nm. but new things pop up all the time in the scientific community. Just use common senses... what reason do you have to point a concentrated beam of light at your skin lol... good luck.

michael.

Ash said:

If your 405nm laser really is <5mW, you have nothing to worry about.
Even with a more powerful 405nm laser, you don't have to worry about UV, because the 405nm laser is really near-UV, it's in the "visible" part of UV. Just don't shine it into your eyes (or reflect it off of a mirror into your eyes) and you should be fine.

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Dr Kemmler said:

Great, good to know.

Also, thanks for the correction on milliwatt. I'm actually a grammar nazi when it comes to forums but I've only heard the term spoken (and only recently) aloud so was pretty much going with a phonological spelling.

Yeah my laser is <5mw it says so on the model itself, unless it's lying to me...
so I think that's all I may ask around here since I'm not into customization or builds so many thanks again for your help everybody!

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A 405nm laser (violet/purple) is no more dangerous than any other laser with the same power density.

That said, please bear in mind that most cheap 405nm lasers are actually quite a bit more powerful. A <5mW 405nm laser would appear VERY dim.

A 150mW violet laser appears to be about as bright as a 10mW green laser.

If this is a cheaper laser, DO NOT trust that label. If you attempt any kind of burning you need proper safety goggles. Be very careful about reflections. While it isn't likely that the laser is very powerful, 405nm pens do show up that are >40mW quite often.

There is no need to be worried about UV specifically, but any laser should be treated carefully, and your laser is probably well over 5mW.

InfinitusEquitas said:

If this is a cheaper laser, DO NOT trust that label. If you attempt any kind of burning you need proper safety goggles. Be very careful about reflections. While it isn't likely that the laser is very powerful, 405nm pens do show up that are >40mW quite often.

There is no need to be worried about UV specifically, but any laser should be treated carefully, and your laser is probably well over 5mW.

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This is very true.

A picture of the dot on a white wall and another pic of the dot on a dark-colored surface may help us to determine if your laser is above 5mW (and a rough estimate of how much over).

Virtually all of the cheap '5mW' 405nm pens are far in excess of 5mW. I have one on my desk right now that meters 83mW just like it came, using fresh AAA's, with no modifications. An actual 5mW 405nm laser wouldn't sell well due to the lack of visibility of the wavelength.

The biggest concern concerning UV wavelengths (or in this instance, near UV wavelengths) is that the eye does not respond as quick/well to the light from it. A 532nm laser (green) of a fraction of the power will cause your eyes to react by your pupil closing and the blink reflex if exposed close enough to your eye.
A much higher powered 405nm will not cause the same thing to happen. Your eye will remain dilated (open) and you may not even trigger a blink reflex with a direct hit to the eye (depends on individual sensativity.)
So the higher powered but less visible laser could cause permanent damage while the lesser one would seem brighter/more powerful.
Be safe with it. Be aware of reflections.

As far as exposure to "radiation" goes, you have more UV from a blacklight or the sun for that matter. And the sun doesn't have an off switch.

I would agree with the above: the more visible the wavelength, the better any avoidance response will be. Since 405 nm is a bit on the border of the visible, your blink reflex may not be as prominent as it would for a 532 laser of equal power. You get the same problem going towards the infrared, where the light may seem so dim you do not realize you are in any danger until it is too late.

Unfortunately there is not much information about the relationship between wavelengths and the speed/sensitivity of the optical reflex, and its also subject to some variation between individuals at the edges of the visible spectrum.