405nm 1mW pointer - need advice about goggles

[wosser]

Hi there,

I'm building a project that requires a laser that emits light down in the 405nm region , or thereabouts at a low intensity (if you're interested, I'm using a CNC machine to move the laser around to expose UV-sensitive coatings on blank PCBs).

My question is: can anyone recommend a suitable set of eye safety goggles compatible with a laser of this kind?

My eyes are obviously priceless but I see that some of the professional goggles are way up in the $120 price bracket! Is there a cheaper alternative that would protect me from this low-power laser?

:thinking:

Also, because this thing emits UV, how much more dangerous is it than say a 1mW red laser?

Thanks for reading

 

[grainde]

There are loads of threads about laser safety goggles. Have a look at this one it has lots of information and links to several cheap pairs of glasses that should meet your needs: http://laserpointerforums.com/f53/get-some-safety-goggles-now-75799.html

Good luck :beer:

BTW if your laser has been tested at and really is 1 mW, or less than 5 mW, you can operate it without goggles. I still wouldnt stare at the dot though!

Edit: Just for info, if you havent tested your 1 mW laser and it hasnt been checked, cheap pointers in the 405 nm region are often way over spec. See this thread for details: http://laserpointerforums.com/f52/cheap-ebay-pointers-some-interesting-lpm-results-73993.html

 

[ZRaffleticket]

If it is 1-4mW I wouldnt really worry about looking at the dot for a while. As long as you're not having a staring contest with your laser you shouldn't have an issue; PROVIDED IT'S AROUND THE LABELED POWER.

Edit: However, 405nm lasers are notorious for being far overspec when labeled at low powers... my old 20mW one metered around 80mW. Some people's 5mW's go around 60. Just get it checked and tuned down (if overspec, and if possible)

Edit 2: It's NEAR-UV, it's safe in that respect. The danger zone is UVB and wavelengths there aren't available in diodes.

 

[wosser]

Hmm, that's a bit unnerving.

Since this laser cost me a colossal £4.95 (plus £2 shipping!), perhaps it might warrant some kind of measurement before I start the project, just to be on the safe side.

Do you think it would be feasible to measure the power output myself? I'm into electronics as a hobby anyway so I've got a decent set of test gear (DMM, oscilloscope etc).

Thanks for the help so far guys, I'm a little less terrified of this laser now I know a bit more about it.

 

[grainde]

The chances are (and especially at that price) the laser will be way over spec, so yes you'll need a pair of goggles.

Also, if you put in your location someone might be able to help you LPM your laser to confirm its power.

If you want to build a LPM yourself there are a few theads about that. Heres a compilation Lasersbee made. The cheapest Im aware of is the Mariomaster thread and it will cost you ~$50. :beer:

 

[ARG]

Edit: However, 405nm lasers are notorious for being far overspec when labeled at low powers... my old 20mW one metered around 80mW. Some people's 5mW's go around 60. Just get it checked and tuned down (if overspec, and if possible)

My 5mW 405nm pen metered at 75mW You can never be sure of the power unless the laser has been tested on a LPM.

 

[wosser]

I never knew lasers could be so fascinating. My pointers arrived today and I'm pretty damn sure they are waaaay over the stated wattage. I do have an old red 1mW alignment laser and that is pathetic in comparison with these UV/purple ones.

Now, I've been doing some science!

Have a look at this blog post I've just written...
Wardy's Projects: Using a Laser to power an ATTiny5

I've been super cautious with the devices, pointing them at a matte black surface indoors and the dot is still probably 2 or 3 times brighter than my old red alignment laser.

So yeah I'll grab myself some of those Eagle glasses I've seen talked about on here somewhere.

I'm somewhat alarmed that you can get such bright lasers for less than £5.

Thank you everyone for the help and all the links. My eyes appreciate it


Cheers.

Wardy.