World first high power underwater handheld laser

[GSS]

If anyone is going to use this in a swimming pool when they get it, make sure you wear your glasses without exception. When taking this profile pic, the water was way choppy, and the beam was dancing all over the place; it'll b the same under the surface. If you have a round swimming pool, it will reflect into your eyes. I would also like to see how quickly one of these can burn into a pool lining, because the effect of convection of the water should help reduce local heat, but the radiation is very localized. Anyone willing to sacrifice their pool? For science.

Well said and thanks for the warning:beer:
I'm not planning in the anywhere future for a under water laser but I hate to admit I probably wouldn't of thought of number of possible reflections

 

[Encap]

This is definitely a neat laser. If I was still in a decent area for diving, I'd like one in 520nm or maybe 638nm though. The blue just doesn't seem to scatter and stand out enough. Blue transmits more effectively, but that leads to a lot of blue light in the background and less light coming back to see. Something that doesn't transmit as well would probably have a much more visible beam for a shorter distance.

405nm is great underwater to play with fluorescence, so definitely a version to consider. No idea how visible it'd be though.

As mention in post #8,
"The reasons that there aren't many applications of lasers in an
underwater environment is associated with the way light is transmitted
underwater.

There are two distinct causes for the energy loss of a light signal in seawater:
one is absorption and the other is scattering - 2 separate problems:

A. Most light is absorbed by water -- Water absorbs ultraviolet,
yellow and red and infrared radiation very strongly, so that beams in
these spectral regions cannot be transmitted very far -- meaning that
systems using such lasers are pretty useless. On the other hand, water
(seawater, that is) transmits blue-green light pretty well -- losing
"only" about 5% of its original intensity for every meter it transmits
through water.

B. There are often little specks of dust, tiny animals
(phytoplankton), and tiny plants (photoplankton) in water, and these
reflectd a little bit of the light, too, reducing intensity as it passes
through water. This adds to the problems noted above in Item A.

The effect of these two effects is that lasers used underwater have to be
much more powerful than those used in air, where absorption is generally
much lower than in water."

If anyone is going to use this in a swimming pool when they get it, make sure you wear your glasses without exception. When taking this profile pic, the water was way choppy, and the beam was dancing all over the place; it'll b the same under the surface. If you have a round swimming pool, it will reflect into your eyes. I would also like to see how quickly one of these can burn into a pool lining, because the effect of convection of the water should help reduce local heat, but the radiation is very localized. Anyone willing to sacrifice their pool? For science.

Well said and thanks for the warning:beer:
I'm not planning in the anywhere future for a under water laser but I hate to admit I probably wouldn't of thought of number of possible reflections

excellent points--reflections, eye safety, and laser goggles use are always a concern and consideration with laser use regardless of environment they are used in.

 

[Benm]

I doubt this would be a big problem with scuba diving though, you can use lasers under water to point out interesting things to look at just fine.

Obviously you should take care not to shine people in the face, but the reflections are not that big of a probem: you'd be mostly pointing downwards to highlight some creature in a coral reef or something like that... not poiting up where the air/water boundary could be quite reflective and send a dangerous amount of light back at you or fellow divers.