beam reflected on skin could be dangerous for the eyes?

[gbravetti]

Hi,

I'm working on a laser instrument, like a laser arp but is just a single beam.
It could be dangerous for the crowd or for me to see the beam reflected on my hand/fingers?

I'm using a 40USD 200mW 532nm Green Laser Module (3V 11.9mm)

Thanks!

 

[Flaminpyro]

probably not unless you eye is only 1mm away from your skin that the laser is reflecting off of...

 

[gbravetti]

oh no, the crowd will be at several meters and I will be at not less than 50cms, anyway the idea is that I won't see the beam reflected on my hand, but may be I'll see some little reflections on my fingers.

I'm new to lasers, I read that reflections could be dangerous specially on glossy surfaces, I know that skin is mostly mate but I think better to ask than to regret.

Thanks!

 

[Bluefan]

Even when there is something relatively shiny on your fingers it won't be a plane surface giving a collimating reflection that would be dangerous, only uncomfortable. So you'll be fine, the only thing is that 200mW may be painful for you if you keep your hand steady in the beam.

 

[gbravetti]

well, I think my laser is not a real 200mw laser, to feel something on the skin I have to put the hand very close keep it very steady for some seconds. I was playing some time ago with a real 200mw laser and I remember that you can feel the laser on skin almost immediately.

 

[magmabeam]

How small is dot? Smaller dot = much brighter diffusion.

If you don't feel the beam heating your hand up within a like 5 seconds that would suggest it's not that powerful so light diffusion won't be great enough to cause problems.

 

[Isoleucine]

Magmabeam is correct. Concentrated light in a small area will reflect in a greater magnitude.

This doesnt pose a problem unless they are 400-475nm lasers in excess of 150mW. But then again, nearUV lasers could cause skin problems and great damage to the eyes.

 

[Bluefan]

The dot size doesn't matter for how much it scatters, only how the scattering is distributed. 400-475nm lasers do not cause skin problems besides burning them like any other laser. This wavelength reagion may be absorbed better and thus burn you faster, but it's by no means the effect of a UV laser.