I recently bought a 1.25w blue laser pointer and I was doing the usual pointery things such
as burning matches, popping balloons etc, when I inadvertently caught my finger in the beam.
Man, was that hot! Ow…but how hot was it? Can anybody tell me just how hot these things can get?
It’s not necessarily “how hot” - it’s the overall power, and one-plus watts is not insignificant when localized on a 1/50" circle. Heat would depend on how much of the light energy transferred to whatever object you’re applying it to.
One Watt is a pretty substantial amount of laser power. I once stuck my finger in a 1W infrared beam, and it did feel hot.
But laser pointers don’t go that high, as a rule. I understand that there ARE 1 Watt laser pointers on the market, but the last time I checked they weren’t easy to get. They ought to be banned – they can be a significant hazard, especially to eyes. And you don’t need a watt to point things out on a PowerPoint presentation.
That said, I’m surprised that you could get a blue laser pointer that can cause significant sensation, let alone pain. even allowing that blue might be more efficiently absorved by your finger, I wouldn’t expect it to cause a sensation of heat. If it can do that to your finger, it can certainly do that to your eye as well. BE EXTREMELY CAREFUL WITH IT. Don’t point it anywhere near anyone’s eyes.
I’m alsp very surprised at the mere idea of a blue laser pointer. Blue doesn’t show up extremely well – the eye;s response is falling off there. The eye response peaks in the green, so green laser pointers make a lot of sense. But blue doesn’t – you have to work at it to create a blue laser for your hand, either making a blue laser diode, or frequency-shifting a longer wavelength laser diode. That’s why we have red laser pointers – they were relativel easy to make. But why blue? If you go to one of those laser light shows, you’ll notice that the blue patterns are dimmer and harder to see than the red, green, or yellow ones. hy go to all that trouble to make a dim laser pointer?
It’s far from a dim beam…it shows up very brightly in the night sky.
It’s not for pointing at screens as it’s too powerful but I always use safety goggles
when I use it. The sting on my finger felt remarkably hot and I certainly won’t be that careless
for a second time!
Wait until next October… they’re coming out with a pink one.
You know, for [del]kids[/del] boobs.
You can have some real fun with it if you pop down to the local airport and shine it in the pilots eyes as they come in to land. If it is a military airfield - so much the better.
Solid state lasers (direct and diode pumped) have really come a long way and there’s no reason to think that these numbers are not real. I’ve played with both red and green pointers (battery powered, momentary button, stick form factor) that were over a watt and were pretty clearly melting and burning stuff. We used the red one to write one dark plastic. They both scare the hell out of me.
True, the power outputs are often exaggerated but heres some examples:
2.5W blue for $300
Half watt green for $113
2W Green for $189
As I said, I knew about the 1 W nes, but I’m surprised by the claim of a 2.5 Watt blue hand-held laser. This SHOULD scare people. There is already legislation against some of these devices in some places.