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A sign for inadequate laser goggles?

Krom

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Hi, I'm fairly new to the forum but own a few low power lasers and got my first high power one, being the PL-E mini 400mw 532nm from Jetlasers.

I bought the goggles that Jetlasers offers when purchasing the laser, and they are labeled as 190-540nm OD4+.

The thing that made me concerned is that while I was burning something with the goggles on, and viewing the dot from about half a meter away, I could see a green light coming through the goggles, like a small green LED right at the burn point. Everything else seen through the goggles including the rest of the light coming off the dot is red.

Is this normal? Is there an easy way to test the goggles without a LPM? is OD4+ usually sufficient for a laser with this power?
 



Wheatfie1d

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The goggles from Jetlasers should be pretty safe. Just remember it is a laser so obviously the end of the beam is going to be extremely bright. A small amount of light coming from the brightest spot is going to make it through the goggles and is not going to hurt you. Although not advised at all, you could probably look at the dot on the wall for a reasonably short period of time without glasses without doing any harm. Still, always be careful and make sure you don't shine the beam directly at yourself or any living thing.
 

paul1598419

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A pair of OD4 goggles should take a direct hit from a 1 watt laser, but the light from that should not be more than 0.1 mW. They reduce the specular reflection by a factor of 4. That would be one ten thousandth of the power of your laser. It would be unusual for a 400 mW 532nm laser to look green through the goggles. Even a diffuse reflection like off a wall should look basically like the color of the lenses.
 

Coonie

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A pair of OD4 goggles should take a direct hit from a 1 watt laser, but the light from that should not be more than 0.1 mW. They reduce the specular reflection by a factor of 4. That would be one ten thousandth of the power of your laser. It would be unusual for a 400 mW 532nm laser to look green through the goggles. Even a diffuse reflection like off a wall should look basically like the color of the lenses.
No plastic goggles are meant for direct hits. Only glass can withstand it and protect the wearer.
 

paul1598419

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There are many different plastics. That said, how do you know exactly what these goggles are are of? If they are indeed an OD4+ pair of goggles, they will protect one from a 10 watt specular hit reducing the the power to 1 mW. I m gong by the printed reference on the goggles themselves.
 

Encap

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You should NEVER stare directly into a laser beam.
Laser safety glasses are designed to protect your eyes against an accidental direct or diffuse exposure of the laser beam.
The length of time a pair of laser safety glasses would survive a direct hit will depend on the irradiance/power per surface per unit area of the beam and the materials the glasses/goggles are made of.
 
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paul1598419

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Exactly. These goggles were never meant to protect against a prolonged exposure to laser light.
 




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