laser visible through goggles

[poofjunior]

Hi everyone,

I recently picked up this laser in the link below: a ~1.5 [w], 445 [nm] laser that I'm driving with a lm2941.

1 5 2W 445nm Blue Diode in Module w Leads Aixiz Glass | eBay


I also picked up a pair of goggles from safetyglassesusa.com.
LSI Laser Safety Glasses with Filter 110

The glasses are 0D6+ from 192-532[nm], so 445[nm] is covered, although I'm a bit concerned because the focused laser is still visible through my goggles as a small dim dot, when I was under the original impression that safety goggles will completely inhibit my view.

As a side note, I'll mention that the raw laser is very bright (as seen through a phone camera recording).

While slight visibility of the laser is nice for focusing it, I'm worried that the glasses may be powerful enough to damage my eye if a rogue, though reduced-power, beam hits my glasses.

Long-story-short: am I safe, or should I look for better glasses?

 

[mortuus]

Well no the glasses only reduce greatly not block totally the view what i know of. U should be safe the glasses looks like they are good quality.

 

[Zeebit]

That's normal. You should be safe. If it were to block all of the light then it wouldn't be safe anymore. You won't know if the laser is on and where it is pointed at.

 

[Atomicrox]

I'll have to disagree. OD6 passes 1/1000000 of the light. Even if you pointed your laser at the goggles (DON'T) only 1.5uW will reach the other side, which is not visible - you'd need a professional lab LPM to even measure it.

If you're seeing a dot of another color (I see orange or yellow with my goggles) you don't need to worry - that's fluorescence of the target, not the laser itself.

 

[Benm]

And why would 1 uW not be visible?!

If you were hit directly into th eye with a 1 mW laser beam (just 1000 times more powerful) it would be blindingly bright, possibly painful, and even damaging on long term exposure.

The matter seems not to be looking into the laser (which i would recommend against regardless of what goggles you have), but looking at the projected dot onto a surface.

Wether you can see that dot trhough OD6 goggles is mostly a matter of ambient light. In would be equal to a microwatt laser in apparent brightness, but you can see a microwatt laser dot in a dark environment.

If you can see the dot in daylight conditions it is more likely that your goggles are NOT OD6 however, which raises the question what amount of protection they do (or, do not) offer.

 

[Atomicrox]

I meant it wouldn't be visible pointed at a matte surface. At least my 3W laser isn't visible at all with Eagle Pair goggles, which are "only" about OD4.5.

After re-reading I acknowledge my post wasn't very clear.

I'll try again at complete darkness on a very low fluorescence surface and see if I can see any blue.

 

[Atomicrox]

Update: finally remembered to test this.

Looked at the dot of a 3W laser through OD4.5 goggles with a diffraction grating in front of them, in total darkness. No blue at all, just "yellowish-green" to red, which looks orange without the grating. Couldn't find any surface that does not fluoresce, though.

On a related note I can see some light from my 520nm 30mW laser pointed at the wall, going directly through the goggles. I'm tending to believe that's LED emission from the diode (at >540nm), since it seems a different, non-coherent shade of green.

 

[mortuus]

Update: finally remembered to test this.

Looked at the dot of a 3W laser through OD4.5 goggles with a diffraction grating in front of them, in total darkness. No blue at all, just "yellowish-green" to red, which looks orange without the grating. Couldn't find any surface that does not fluoresce, though.

On a related note I can see some light from my 520nm 30mW laser pointed at the wall, going directly through the goggles. I'm tending to believe that's LED emission from the diode (at >540nm), since it seems a different, non-coherent shade of green.

Yea same for me if i point my 40mw green through goggles on wall, the dot is very very weak and small.

 

[Atomicrox]

532nm or 520nm? I tried with a ~170mW 532nm and it's completely blocked - probably because the DPSS emission has no residual broadband LED light.

 

[mortuus]

532, its cheap ebay goggles so maybe thats why gonna order better anyways.