How To Turn a Mini Maglite Into a Laser 605
Lucas123 writes "Using the laser from a DVD burner, this instructional video shows you how to create a hand-held laser that is powerful enough to light a match and pop a balloon. There's some soldering involved and the Maglite's bulb housing needs to be drilled out to fit the new laser diode, but with some basic skill, most people could do this. Just plain cool." Update: 07/09 12:23 GMT by KD : Warning, the device that results from following these instructions will blind you if you look into it.
Uhhh... (Score:5, Informative)
Cool isn't the word... (Score:4, Informative)
Um, *excuse* me!? (Score:5, Informative)
Dumbass in the comments (Score:5, Informative)
If you can pop a balloon with it, it is probably in the 100mw range which is enough to do permanent eye damage in 1/100th of a second. That's faster than you can blink. You won't go blind instantly, you'll just burn out a bunch of optic nerves, producing a 'hole' in your vision. Chances are, your brain will correct for the hole and you won't even know its there, unless an object ends up right at that point in your field of view, at which point it will 'magically' disappear.
Re:Nice timing (Score:5, Informative)
Yes. But the main problem is that you need some way to limit the electric current through the diode. Laser diodes behave a bit like LEDs, electrically: below a threshold (2.5 V or so) there is little current and they don't do much, and above that threshold, every 0.1 V you add will increase the current and light output enormously. Too much current and the diode will die in a matter of seconds. Apparently the laser diode he used was just right at 3 V from two penlites, although I doubt that he had a calibrated laser power meter to measure whether the output power matched the nominal power rating for the diode. The simplest way to limit the current is to use a higher voltage and a series resistor. Something else is that the laser assembly in different optical writers sometimes doesn't have the collimating lens attached to the laser diode itself: without lens a laser diode produces a very divergent beam.
Now for safety: I work with fairly high-power lasers (up to 25 W) for a living and consider a hand-held 250 mW laser in the hands of someone without appropriate training in laser safety hugely irresponsible. According to the IEC60825 standard on laser safety, 200 mW will lead to permament eye damage within 1 microsecond (!) of exposure. The reason laser pointers are restricted to 1 or 5 mW (depending on the country) is that for those powers, eye damage will occur after 0.3 seconds, which is about the time for the blinking reflex to close your eyes in the event of accidental exposure. Unexpected reflections from things like glass can be up to 10% of the beam power - 20 mW (eye damage in 10 microseconds).
Mods, wake up! (Score:2, Informative)
This stuff is fun. . . (Score:4, Informative)
http://www.laserfaq.org/sam/lasersaf.htm#safssl2 [laserfaq.org]
Torben
Re:This makes me sad. (Score:5, Informative)
Re:To repeat an old warning (Score:5, Informative)
Re:Dumbass in the comments (Score:5, Informative)
Re:Sure (Score:5, Informative)
One thing to note though is that green laser are more complicated. There isn't actually a single diode that does green, rather it is an IR light that's generated and then frequency doubled to make green. In fact one would probably get more energy per square mm by simply using the IR output. Of course that is even more dangerous since you can't see IR and thus could be lasing your eyes and not know it.
Before you do this, note three things:
1) You can buy lasers over 5mW commercially. Just search Google for it, it isn't illegal or anything.
2) To own and operate any laser over 5mW requires a license. You are responsible for getting it from the FDA.
3) Messing with high power lasers (and yes over 5mW is high power in the laser world) is rather dangerous. That's why there's the limits. If you have a 100+mW laser, which is around what you'd need to light a match, even the reflected light could damage your vision permanently if you hit your eye. Given that you don't seem to know much bout lasers, best not to fuck around with this. Consider that the sun provides about 1000 watts per square meter to the earth, and that looking right at it will damage your sight in a few minutes if you aren't protected. That works out to about 1mW per square mm. So take a laser, who's dot is only around a square mm or two, then consider its power. Yes, it really is brighter than the sun. When you are talking about some of these high power 3B lasers, they are MANY times brighter than the sun. Don't play with powerful lasers until you learn about them.
Re:Um, *excuse* me!? (Score:3, Informative)
Re: Just plain stupid - IR lasers are dangerous (Score:2, Informative)
Freedom of speech or not, it is irresponsible to tempt people with limited or no knowledge to mess with technology that is likely to blind them or others. There is no age limit for readers of this site, so you have to assume that you might be speaking to teenagers or even kids. I would have thought that americans, with their love of lawsuits, would have learnt that by now.
Especially IR lasers (invisible lasers) are dangerous, because they will damage your eyes and you will not even blink or know what happened. The first thing that happens is you feel pain, and the damage is done.
Kids, have a game of soccer instead.... you might actually get a tan and some friends
Re:Nice timing (Score:4, Informative)
Dangerous (Score:5, Informative)
This is a very dangerous toy
IT WILL BLIND YOU IMMEDIATELY IF:
- You look at it
- You shine it on a reflective surface that shines it back into your eye
No joke, people. Don't try this at home. I'd actually argue that this video is irresponsible since it does not mention the dangers of the item being built at any point. It will probably be uploaded on Youtube and a lot of innocent, curious kids will end up with one fewer eye as a result of this video.
DO NOT USE UNSAFE LASERS WITHOUT WEARING THE APPROPRIATE PROTECTIVE GEAR (special goggles can be obtained for specific wavelengths, which will ensure that you cannot see the laser - and hence it can't hurt you).
Daniel (who was paying attention during the Physics Dept 'laser safety' lecture)
Re:Dangerous (Score:5, Informative)
TO EDITORS: PLEASE ADD SAFETY WARNING TO THE ARTICLE SUMMARY!
This is an irresponsibly dangerous video with no safety warning.
Re:Dangerous (Score:5, Informative)
I was in a foreign country. The company I worked for rushed me to hospital and this foreign doctor explains to my collegues that she needs to inject a needle in behind the back of my eye. You need to prevent the back of the eye from bruising and swelling up.
She takes out her book of english and says slowly "This will..... hurt". And it did.
Thankfully after 2 weeks my eyesight was back to normal.
So please everyone - do be very careful. And if anything happens, it is _vital_ to get to a _eye_ hospital as soon as possible.
As much as I hate lawuits... (Score:3, Informative)
I'd rather get shot with a gun than be blinded with that thing. And unlike guns, any asshole (or kid) can assemble one from parts, with absolutely no regulation, and leave me permanently blind.
Don't realize how bad this is? OK, imagine this: Someone brings this to a disco and points it towards the revolving sphere = dozens blinded, permanently. This is not a joke. This can be used for terrorism, pure and simple.
Blinding lasers are banned. (Score:5, Informative)
Weapons that do maim are undeniably effective, since it not only deprives your enemy of the soldier, but also the resources required to provide him with medical attention, and to support him when he is no longer able to be productive. Anti-personnel land mines are the chief example of weapons which fall into a grey area here - most of them are potentially lethal, but most often fall short and leave their targets maimed.
There have been various plans to produce merely incapacitating light-weapons, but in practice, it is difficult to produce a device than can dazzle your opponent [wikipedia.org] without at least some chance of permanent damage.
Re:Dangerous (Score:2, Informative)
Laser diode may not last too long run like this... (Score:5, Informative)
The article simply places the laser diode directly across the 3V battery supply, with not even a ballast resistor to limit the current. You might get away with this with AA batteries, but if someone were to try this trick with a D-cell maglite, they would most likely let the magic smoke out of the laser very quickly.
Re:Dangerous (Score:5, Informative)
As it turns out, my injury was severe but not nearly as bad as it might have been. I was not looking directly at the prism from which the beam had reflected, so the retinal damage is not in the fovea. The beam struck my retina between the fovea and the optic nerve, missing the optic nerve by about three millimeters. Had the focused beam struck the fovea, I should have sustained a blind spot in the center of my field of visions. Had it struck the optic nerve, I probably would have lost sight of that eye.
The beam did strike so close to the optic nerve, however, that it severed nerve-fiber bundles radiating from the optic nerve. This has resulted in a crescent-shaped blind spot many times the size of the lesion.
The diagram is a Goldman-Fields scan of the damaged eye, indicating the sightless portions of my field of view four months after the accident. The small blind spot at the top exists for no discernible reason; the lateral blind spot is the optic nerve blind spot. The effect of the large blind area is much like having a finger placed over one's filed of vision. Also, I still have numerous floating objects in the field of view of my damaged eye, although the blood streamers have disappeared. These `floaters' are more a daily hindrance than the blind areas, because the brain tries to integrate out the blind area when the undamaged eye is open. There is also recurrent pain in the eye, especially when have been reading too long or when I get tired.
Or just buy one with similar power (Score:2, Informative)
No, I don't have one. They're almost certainly illegal in my country.
Re:Dangerous (Score:5, Informative)
http://www.telegraph.co.uk/news/main.jhtml?xml=/n
http://www.criminal-information-agency.com/firear
Re:Dangerous (Score:5, Informative)
Re:As much as I hate lawuits... (Score:3, Informative)
I cannot overstate this, this is not a fart in a bottle.
Laser Safety, Standard Operating Procedures, Gear (Score:5, Informative)
Laser Standard Operating Procedures [csulb.edu]
Laser Safety [csulb.edu]
Check your particular DVD Rom, chances are fairly good that it's rated as a class I laser (non hazardous, but try not to stare directly at it...because like everything else it's probably made in china I wouldn't be surprised if to save a penny they underclassy the mW output to skip a safety inspection over in the usa heh)
However, if it's a class II....
The reason I am offering these links is because I doubt many people know that a class II laser beam will cause eye damage within as little as .026 seconds?
1-2 seconds could be more than enough to cause snow blindness style affects, headaches, and temporary eye tissue scarring?
I got caught not wearing my ansi rated safety goggles at corning from a light gun and I couldn't see for about 3 days (snow blindness from intense UV exposure for 2 seconds). So let's practice some good sense people.
I know about dead optic nerves (Score:5, Informative)
Due to an infection I obtained when I was 2, I've got partial blindness in both eyes. The infection caused scar tissue to form on my retina smack in the good part (center of the optic nerve junction) of my left eye. I can see objects and make out large things but I can't read with that eye at all. Think of it like your peripheral vision. Try this: put a page of text a foot from your ear and try to read it--while looking straight ahead. That's what my vision is like when I close my right eye.
The right eye has some similar damage, but luckily the scar tissue formed only over a smaller area which is not positioned over the center of the optic nerve junction. So back to the parent's comment about your brain compensating, I can tell you from experience--it depends on how much damage there is. I can read, I can drive and so on, but my brain has to work a bit harder to make a complete image. I don't have 20/20 vision (even with glasses), it's more like 20/50. (I can read text at 20 feet that you can read at 50 feet.) I have to hold things closer to read them than most people, and it's pretty hard to read road signs while driving.
So the moral to the story is twofold:
1. Sandboxes are bad, toxoplasmosis bacteria likes to grow there and kids that play in sandboxes inevitably will rub their eyes.
2. Don't mess with lasers. Holes in your vision--not cool.
(I almost died laughing when I saw the "donotlookatlaserwithremainingeye" tag. I have a special place in my heart/right-eye for that line.)
Re:Nice timing (Score:3, Informative)
So did I, to be honest, although never several seconds. But: at 1 mW (visible light), the MPE (maximum permissible exposure) is about 1 second. The MPE represents the largest exposure which under worst-case circumstances does not lead to eye injury for 90% of the population. Worst case means that the eye and the laser source are stationary over the given exposure time, and that the eye lens is focused such that the laser light is concentrated onto the smallest possible spot size on the retina. If the eye lens is a bit out of focus, resulting in a blurry spot, you have some extra margin. I think the MPE values take into account that the eye is never completely motionless.
Re:Sure (Score:4, Informative)
I haven't yet seen a straight green laser diode -- mine are all frequency doubled. However, many new green LED's are created using silicon nitride, essentially being blue lasers that emit at a longer wavelength, and it's not clear to me why they couldn't do the same thing with a blue diode.
Lasing your eyes with IR sucks, but not as bad as with visible, because the front of your eye is mostly (*mostly*) opaque to IR so you'll just fry your cornea, which can be replaced. Visible will go through the eye optics system, get even more focussed, and fry holes in your retina, which is not repairable. I've worked with people who have gotten big blasts of UV, IR, and green, and only the people who got hit with green had blind spots in their vision. The others had to wear glasses or have lens/cornea replacements, but they had reasonable vision despite that.
Re:Dangerous (Score:4, Informative)
Re:Dangerous (Score:4, Informative)
Re:Dangerous (Score:1, Informative)
Except for the fact that they'll have stalled right in front of you and won't be able to pull anywhere, while you're stuck stopped behind them.
Looks like lots of fun - but (Score:3, Informative)
If you shine the beam into your eye - on purpose, by accident - or by bouncing it off of something shiny, it will burn holes in your retina. That's not "may" that's "will". We're talking about permanent eye damage, the kind that makes people blind.
Operating one of these in your house or outdoors is dangerous not only to yourself but to others. Our world is full of shiny things; even imperfect "mirrors" can reflect enough beam energy to harm yourself or an innocent bystander; just one quick "flash" sighting of the beam's reflection is enough to cause permanent eye damage.
I know that there's too many of you who will say "it'll never happen to me" and go happily waving your new super laser pointer around. I have one helpful tip for you: if you have a "wow, that's bright!" experience followed by things getting darker - get yourself to the hospital RIGHT NOW and tell them you got a look at a class IIIb laser. They'll know what to do and can probably save your eye if you get there soon enough.
Laser safety goggles are a great idea - but only if you're playing with your laser indoors in a room with all windows covered and all shiny / reflective things removed or covered. If you take it outdoors and start waving it around, someone's going to get hurt.