Red beam at pool with green laser and safety glasses

[mlira]

Good night folks,

Tonight I was playing around with my 50mw green laser, just pointing at the sky to see the beam and the dot at the clouds. :yh:

Afterwards, I thought to shine it on the pool, but first I put on my focalprice safety glasses on. When I pointed at the sky, I couldn't see any beam at all, but when I pointed at the pool, I could see a well collimated red beam, and the green dot.

I'm aware that my laser has no IR filter nor the safety glasses protect to them, so could that red beam be the IR? It would be strange though, because I've read that the IR light come out of the laser unfocused. What do you think?

Peace

 

[sampson]

Good night folks,

Tonight I was playing around with my 50mw green laser, just pointing at the sky to see the beam and the dot at the clouds. :yh:

Afterwards, I thought to shine it on the pool, but first I put on my focalprice safety glasses on. When I pointed at the sky, I couldn't see any beam at all, but when I pointed at the pool, I could see a well collimated red beam, and the green dot.

I'm aware that my laser has no IR filter nor the safety glasses protect to them, so could that red beam be the IR? It would be strange though, because I've read that the IR light come out of the laser unfocused. What do you think?

Peace

I'm certain that what you are seeing is the 808nm Near-IR. How collimated is "Well".. how big is the spot at ~10 feet? Any chance for pics?

 

[RA_pierce]

I'm certain that what you are seeing is the 808nm Near-IR. How collimated is "Well".. how big is the spot at ~10 feet? Any chance for pics?

Not likely.
808nm is very hard to see with the naked eye even with green blocked out.

What it is is the green beam causing fluorescence in the dye of the laser goggles, which will glow red or orange.
This is because the water attenuates more of the beam, like fog, because it is a denser medium than air. This allows for greater visibility - in this case, enough to excite the pigment in the goggles.

IR light may exit the laser highly divergent, well collimated like the green, or somewhere in between. How much and what kind of beam is leaked really depends on the construction of the laser and can vary from unit to unit.

 

[sampson]

^^ OK, OK.. interesting. Unfortunately I don't have a pool to test with :cryyy: I still do wonder what the picture would look like though.