Red lasers don't burn skin?

[mfo]

Well call me stupid but this is something I've always done when I obtain a high powered laser. I like to see how it feels on my skin lol. My green burns, my purple does too. However...I can barely feel my red. I know it's putting out over 200mW, and it easily burns cardboard. It's really bright to look at. I am guessing this is a wavelength issue?

 

[Shogoki]

yea.. but you figure.. with a high enough power for any wavelength.. you can pretty much burn anything.

 

[charliebruce]

Sub-surface scattering works best at longer wavelengths, and acts to spread the power as quickly as possible through a larger area. The dot should appear out-of-focus and blurry on skin. Try a red dot on a sharpied bit of skin, however, and you'll really feel it

 

[mfo]

Sub-surface scattering works best at longer wavelengths, and acts to spread the power as quickly as possible through a larger area. The dot should appear out-of-focus and blurry on skin. Try a red dot on a sharpied bit of skin, however, and you'll really feel it

Me try!

 

[Cenobite9]

Yes, red lasers sting quite a bit on darker colored skin. Try focusing on a freckle... you'll definitely feel that.

 

[yobresal]

Red lasers burn the crap out of my tattoos but not my regular skin.

 

[mfo]

Red lasers burn the crap out of my tattoos but not my regular skin.

Hmm, so I guess infrared lasers (let's say 200mW?) won't burn either then, right? Unless it's on a dark surface like a tattoo or a freckle.

 

[Deleted member 8382]

shit i tried with one of my freckles and I just hurted lol

 

[Meatball]

Actually, the commercial tattoo removal lasers are infrared. They use longer wavelengths since they burn the surface of the skin, without causing internal damage to the lower layers of skin. 300mw of focused red sure burns me, and will leave a tiny little scab on my skin, not even a millimeter wide. Blu-ray penetrates the skins outer surface better, and can apply more of it's energy to organic materials. Hope this helps.

 

[3zuli]

Red lasers burn the crap out of my tattoos but not my regular skin.

hmm what a idea? :eg: DIY laser tatoo remover? :crackup:

I think red lasers don't burn skin because the inside of body is red-coloured, and it better transmits and diffuses the red light than green or blue
just take a 5mW red and about 50mW green and shine it trough your finger and you'll see

 

[mfo]

So will IR burn bare white skin or does it fail like red 650nm?

 

[Meatball]

IR should do fine on just about any color of human skin. They had to design these tattoo removal lasers with this in mind. Naturally, 650nm can burn as well, you will just need more power to do so. The IR lasers used are q-switched as well. Each pulse can last about a fraction of a second. Each "dot" where the laser hits is about a quarter - inch wide. So you can see why they say that the removal process is much more painful than the actual tattoo was.

YouTube - Laser Tattoo Removal

Ouch...

 

[mfo]

IR should do fine on just about any color of human skin. They had to design these tattoo removal lasers with this in mind. Naturally, 650nm can burn as well, you will just need more power to do so. The IR lasers used are q-switched as well. Each pulse can last about a fraction of a second. Each "dot" where the laser hits is about a quarter - inch wide. So you can see why they say that the removal process is much more painful than the actual tattoo was.

YouTube - Laser Tattoo Removal

Ouch...

Haha nice. I hate when people get dumb, meaning less tattoos just to fit in. The "tramp stamps" especially piss me off.

 

[Deleted member 8382]

Wait. the IR lasers acts over the black tattoo, not over your skin. IR at big powers will ofc burn your skin, but at 200mW it will fail just as red (if it's light skin)

 

[Sybiria]

@meatball
Now that hurts! And instantly!
It hurt just looking at it, no laser touches my tattoos PERIOD!

 

[photonaholic]

Haha nice. I hate when people get dumb, meaning less tattoos just to fit in. The "tramp stamps" especially piss me off.

Love those!!!