Choosing Goggles

[rtavk3]

I am building a ND:Yag DPSS laser using a 20w 808nm diode bar.

I am kinda paranoid about vision safety, is there anything wrong with going with od7+ glasses that cover the 800-1100nm range.

Are there any other wavelengths other than 808 and 1064 I need to protect against if I am not using a frequency doubler?

Are
DBD - YAG, 808nm, 980nm, Harmonics [NR-DBD-00FDA] - $175.00

good enough to protect me against any and all adverse events while working on building this laser? I dont plan on it happening but basically i want to be secure knowing that even if the worse happens and i somehow find my face directly infront of the diode bar that these will protect me for the time it takes to move my face
And the same goes for the ND:Yag laser.

Also in the future after I get something going in the 1064nm 2-3w range I was going to try to scale things up to 30-40w for a laser engraver/cutter mod on my cnc plasma cutter.

Would these goggles still be workable then? Not sure I can go any higher than od7+ so if not then what do people do who work on lasers at those powers?

Any help is greately appreciated!

 

[Bluefan]

A EN207 certification isn't listed, that tells you how high power density the glasses can withstand. OD 7 is for CW lasers plenty, what becomes important is if they can withstand the power. If they would be rated D L5 (that's for CW) for the relevant wavelength they can take up to 1W/mm^2, if they are rated D L6 they can take op to 10W/mm^2. In those cases they need a minimal OD of 5 or 6.
A rating of D L7 would require OD 7, but those plastic goggles will break under 100W/mm^2, so the OD won't be the problem. That's why the plastic filters can have high OD values, but aren't rated very high in CW power density compared to glass filters, but those are expensive. I've seen goggles rated OD 10 and D L4. That means it has a high OD but can fall apart above 100mW/mm^2.

In you case the diode bar probably has a 10mm wide emitting area and if the resulting beam of 2-3W 1064nm is about 2-3mm^2 you can use goggles rated D L5. Then you're safe in case of a direct hit of 1064nm and safe against headbutting the diodebar (the diode bar is still a bunch of diodes which have a large divergence). The goggles you have in the link aren't EN207 certified, but are most likely very good for this. They also block 532nm, should you want to use frequency doubling (or just for any other green or blue laser).

 

[FrothyChimp]

Here is the search results for 808nm and 1064nm. You can get better VLT at a better price for both 808nm and 1064nm: Search Results : OEM Laser Systems, Inc., Precision Laser Equipment and Accessories

Here's the search for 808nm, 1064nm and 532nm in case you wanted to try SHG: Search Results : OEM Laser Systems, Inc., Precision Laser Equipment and Accessories

If you intend to try q-switching feel free to give us a call. We will help you determine the right filters for a q-switched system. The assumption is for cutting or engraving you will be using a q-switched system with an average power of 40W.