Help with 980nm safety

[laserartfan]

Noob here. I'm looking to create art utilizing a laser in the landscape. First and foremost I want to be safe for myself, others and the environment. I have already purchased a laser and safety glasses but I realized I don't know if I am being safe. I have chosen not to power on the laser until I know I am being safe.

The laser and safety googles I bought:
980nm 100mW IR Dot Focusable Laser Diode Module w/ Driver Board 12V Adapter
UVEX DVO Safety Goggles Diode, Yag & CO2 Lasers OD 3 @ Vis to 7+ @ 10.6

Why infrared?
I realize this is likely a more hazardous laser to operate. I chose an infrared laser because I do infrared photography and I have a camera that is sensitive to infrared light. My artistic idea is to use "invisible" light to

My safety concerns:
My understanding is that cheap lasers from China can be unsafe. I purchased this laser enthusiastically before looking into laser safety. From what I understand, the cheaper lasers can emit light outside of the specified spectrum. Is this a concern with this laser I purchased? Did I purchase the right safety goggles?

I specifically want to use this laser outdoors in nature (illuminating canyon walls). According to Laser Hazard Distance Calculator my understanding is that I should be at least 10 miles from an airport (I plan to never point the laser in the direction of any airport). The nominal safe operating distance is 71 meters and the minimal operating distance is 23 meters. I feel like this is a reasonable distance to ensure other people will not be in danger.

As I understand, this is a class 3b laser which means it can burn a material if the laser is held long enough on a material at close range. Naturally, I intend to not leave the laser on a material for any considerable amount of time. But is there a safe operating distance for not burning a material? Is this the same distance as stated above, 71 meters is nominal and 23 meters is minimal?

 

[Snecho]

I don't know anything about what you're trying to do with it, but as far as I know UVEX are not laser googles.Look for Eagle Pair.

100mW is not enough to burn anything unless focused to a pinhead up close. Sounds like you will be projecting a dot dozens of feet in diameter if you want to illuminate a canyon or wall in IR.

You would also probably need a much more powerful laser.

 

[laserartfan]

I don't know anything about what you're trying to do with it, but as far as I know UVEX are not laser googles.Look for Eagle Pair.

100mW is not enough to burn anything unless focused to a pinhead up close. Sounds like you will be projecting a dot dozens of feet in diameter if you want to illuminate a canyon or wall in IR.

You would also probably need a much more powerful laser.

The idea is to draw a line across the canyon wall at a distance of no more than 100 yards.

I've included an image of the goggles which state printed on them:
"For viewing of diffuse laser light only. OD 7 @ 190-380nm, 3-4 @ 740-785nm, 5+ @ 785-1063nm, 7+ @ 4064nm, 5 @ 10600nm"

 

[Snecho]

The idea is to draw a line across the canyon wall at a distance of no more than 100 yards.

I've included an image of the goggles which state printed on them:
"For viewing of diffuse laser light only. OD 7 @ 190-380nm, 3-4 @ 740-785nm, 5+ @ 785-1063nm, 7+ @ 4064nm, 5 @ 10600nm"

Okay, those goggles SHOULD work for your purpose.

Do you mean draw a line via long exposure?

 

[laserartfan]

Okay, those google SHOULD work for your purpose.

I think my concern is how do I know the laser I bought is actually 980nm and safe with these goggles? Would it be safe to start a long exposure, turn on the laser and shine it through the goggles, turn off the laser and end the exposure? This should show if the laser is correctly blocked by the goggles and allow me to close and divert my eyes while the camera records what is happening.

Do you mean draw a line via long exposure?

Yes, that is the idea. To mark/highlight different geological changes.

 

[Snecho]

I think my concern is how do I know the laser I bought is actually 980nm and safe with these goggles? Would it be safe to start a long exposure, turn on the laser and shine it through the goggles, turn off the laser and end the exposure? This should show if the laser is correctly blocked by the goggles and allow me to close and divert my eyes while the camera records what is happening.

It all depends. Where did you buy the laser from originally?

 

[laserartfan]

Where did you buy the laser from originally?

As a new user I can't link to the ebay page, maybe you can copy/paste:

ebay dot com/itm/980nm-100mW-IR-Dot-Focusable-Laser-Diode-Module-w-Driver-Board-12V-Adapter/133200323603?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m2749.l2649

 

[Snecho]

As a new user I can't link to the ebay page, maybe you can copy/paste:

ebay dot com/itm/980nm-100mW-IR-Dot-Focusable-Laser-Diode-Module-w-Driver-Board-12V-Adapter/133200323603?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m2749.l2649

Jeepers dude, that was sent straight from Wuhan. I hope you disinfected it when you got it lol.

Knowing it's from eBay is good enough. I would trust it is at least very close to 980nm but the only way to be sure is to test it with a spectrometer. And I'll be honest, at only 100mW and the fact you'll be using at quite a long range, goggles aren't even really necessary. Unless of course you are pointing at rocks that are reflective. I would trust those goggles as safe for your purpose as it's printed that they block 980nm. Other than that I'd say you're set.

 

[hwang21]

I would guess that your 980nm laser is 980nm +/- 5nm or so. It should not be emitting any light beyond that range. With 100mW, it will likely be able to burn/melt dark-colored plastics/wood if they are placed at the focal point of the laser beam. The safe operating distance for not burning will be "away from the focal point of the laser beam" - there is no formal calculation without knowing exactly the divergence of the laser and the optical properties of the focusing lens

As far as your safety goggles go, they state OD5+ @ 785nm-1063nm. An OD of 5 means that it attenuates light intensity by 10^5 - 100mW would become .001mW. It is commonly accepted (at least for visible light) that 5mW for 0.25 seconds is the limit to avoid eye damage. As 980nm is still fairly close to the visible light range, I would say that you are well-protected, at least for 0.25 second hits. Laser goggles are meant to protect against accidental hits, not deliberately staring into a laser beam or anything like that

 

[laserartfan]

Jeepers dude, that was sent straight from Wuhan.

LOL, I actually bought it several months before the outbreak, but who knows what else could be on it...

 

[laserartfan]

The safe operating distance for not burning will be "away from the focal point of the laser beam" - there is no formal calculation without knowing exactly the divergence of the laser and the optical properties of the focusing lens

Thank you, this makes sense.