High power green laser pointer fun *pics; 56k warning*

I dont think the limit in the UK can be 1mw? I have a stage laser light which is rated at 45mw and its certainly not illegal for me to have it.

 

IIRC there's a classification (thus power limit) difference between laser modules - what you have - and laser pointers.

- H.

 

How visible the beam is depends on atmospheric conditions. If there is lots of dust or moisture in the air, it will be visible. If it is a very clear, dry night, you won't see a thing. And of course, it only works at night.

I don't think a laser will have any practical application as a signalling device for backpackers. And remember, a green laser can cause eye damage from quite a distance, so it is not something to liberally wave about.

 

Greatland make/market lasers as distress flares, though these seem to project a line, rather than a spot to help guide in SAR teams.

- H.

 

Other thing is that a laser is very bright when you're looking at it, but the scattered light due to dust is pretty dim. Remember that you're trying to produce a device to bring people's attention to the hiker, rather than necessarily to pinpoint them once the searchers know the general area. Chances are, unless it's pretty bright you'll miss it.
You're probably better off with either some form of pyrotechnic (smoke grenade, Schermuly (parachute flare), miniflare, etc.). One alternative is what they use for jungle navigation - a helium baloon on the end of a long wire. You send it up, and they send out a helicopter to find it and tell you where you are.

 

wow...


Anyway.. cool laser, dom thanks for the pictures!

 

Are you commenting on something I said almost two years ago?

Wow...

 

Walk around with it on your head and go:


"I am Locutos, of Borg."

Just don't say it to anyone, just kinda do it to the wall or something, and have your camera set up to take a picture so you can show someone afterwards

 

So then gents, how do we go about building a handheld 1W laser pointer?

Edit: TWO YEARS OLD? Oye, the photos still work, too...

 

I don't think semiconductor laser diodes can take that much power. You would need a gas laser. And seing as that would drain AA batteries faster than you can say "uh oh my face is melting" you would need a bigger power supply arrangement also.

 

Hrm. Well i did find a site offering 2000mW units...

 

convert this to work on battery power

 

Yeah they made a mistake on that description. It's actually 0.9mW.

I saw an even worse mistake in a dodgy lighting equipment shop. It was selling a "50 megawatt laser module" obviously not realising the little 'm' actually meant 'milli.'

 

ahh, i was a little suspicious of that description when i looked at the price. Couldn't be bothered double checking, it was too late.

 

Army surplus? After all, there was that Star Wars programme that never took off...

 

Looks that way now, doesn't it?

 

http://www.nostalgia.com/large/70918.JPG

 

The beam scatter is almost guaranteed in most atmospheric conditions, depending where you live, due to our recent trend of metropolitan air quality. The dense carbon pollution of the locale will scatter the beam much more readily in broad daylight, depending on the locale.

As for a laser's implementation as an emergency signaling device, it's not that bad of an idea. They are lightweight and their beam concentration is needed to reach passer-bys across, say, a mountain valley. Battery replacements can be plentiful and are very lightweight. You can see the necessity in carrying both a flashlight and a laser signaler as a laser won't illuminate a dark path while a flashlight won't reach a distant observer during peak hours of the day.

 

Most handheld lasers that are used as emergency signalling devices actually emit a slightly dispersed cone of light, rather than a focused beam. The idea is that you sweep the beam across the helicopter's/plane's line of vision so the pilot sees a bright flash emitting from the area where you are stranded when the beam shines (more or less) straight at him/her. The beam itself is not visible from any distance.

Red lasers are preferable in that scenario, as they manage to last longer on a given battery charge. Green lasers are extremely hungry, and thus not much good.

 

red lasers would also be better as red does not interfere with night vision.
(And by night vision, I mean the biological kind - not the electronic kind.)