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How To Turn a Mini Maglite Into a Laser
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.
So basically you're not making a laser, you're just moving a laser from a drive into a flashlight case.
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What part of "This product contains a Class 2 laser. Do not power on without enclosure" did you not understand? This has the potential for causing serious bodily harm, including but not limited to permanent blindness!
"No problem. I have the capacity to do infinite work so long as you don't mind that my quality approaches zero."-Dilbert
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.
When information is power, privacy is freedom.
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).
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It depends. In nickels (4.5g), the dollar is about 5 bucks per pound. If you use quarters (5.67g), you get about 20 bucks.
It's always a long day... 86400 doesn't fit into a short.
With a 245mW laser, that should be modded informative, not funny. It is strong enough that it can cause permanent eye damage from a reflection, long before the blink reflex kicks in.
If J.K.R wrote Windows: Puteulanus fenestra mortalis!
Green lasers can put out more energy because of their design in general. Now from the demo, it looks like this red diode is more powerful than the ones normally used in laser pointers, not sure on its power. I don't know what the maximum is, but it is in the 100s of mW. I don't know about the orange or blue diodes, haven't really looked at them. The problem is that they are rather expensive so I don't think you'll want to buy them. D batteries have the same voltage as A batteries, just more storage capacity. So using those will make it last longer. As a practical matter, the voltage you feed it needs to be whatever it was designed to take, so if 3 volts is what is called for, do not go over or under that, you'll probably just screw up your stuff.
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.
What the article doesn't, and should say:
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)
Carpe Diem
Such weapons are illegal under the Geneva Convention, as is any other weapon expressly designed only to maim. Laser weapons also have further clarification in the form of The UN Protocol on Blinding Laser Weapons.
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 without at least some chance of permanent damage.
Laser diodes generally require some type of current limiting to prevent damage. In the DVD burner circuit, that is the function of the third pin on the diode package (that the article simply blows off as "not used"). This pin connects to an internal photodiode, which is used to measure output power, and provide feedback through an external driver circuit to continuously control the current applied to the laser diode junction.
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.
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Laser Standard Operating Procedures
Laser Safety
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.
[so much for the modding I'd done in this thread.]
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.)