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.

Uhhh...

So basically you're not making a laser, you're just moving a laser from a drive into a flashlight case.

Re:Uhhh...

Yes, thank you for repeating the article summary.

Dangerous

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)

Re:Dangerous

Apologies for replying to my own comment...

TO EDITORS: PLEASE ADD SAFETY WARNING TO THE ARTICLE SUMMARY!
This is an irresponsibly dangerous video with no safety warning.

Re:Dangerous

Pfft, it's "just plain cool" - ain't no way it can be unsafe!

Next week on /. - how to convert your BB gun to fire 9mm rounds!

Re:Dangerous

Actually, if the little turds use one of these modified pointers, you can easily find and pound their asses.

Jacking up the power like this make the ENTIRE BEAM visible, not just the point.

I still want a laser powerful enough to deface bumper stickers and write insults into the paint on cars...

Re:Dangerous

Jacking up the power like this make the ENTIRE BEAM visible, not just the point.

Visible means little when you're blind.

Re:Dangerous

I'm increasingly of the opinion that the only proper way to pounish somone who intentionally wounds/maims someone is to do the same thing to them. Only withplenty of warning so they have time to get really fucking scared. No other punishment really means anything in the end.

And therefore, you will apply the same theorem to teeth???

Re:Dangerous

You mean to teach people with such crippled intellect and no social or emotional control that they would take from or harm people for their own fun ... well to teach them that there is no consequence to their actions? Good idea, that'll stop them.

Please, pull your head out of your ass. The lack of oxygen is causing brain damage. You are confusing a nice ideas with the reality of human nature. There will always be asshats who don't and won't care about others, will take from others or harm others to satisfy their own pleasures, and only avoid these avenues when they cause discomfort for themselves. So good idea, let's remove consequences for bad behaviour.

Re:Dangerous

Which is pretty much the way it used to work. But nowadays, it's equal treatment for all, equal rights for all, no matter how they treated others or how they trampled the rights of others, the nanny state will protect them all!!

I'm with you. Beat and then neuter the fuckers.

Warning.

Visible means little when you're blind.

Warning: Do not look into LASER with remaining eye.

Re:Dangerous

Next week on /. - how to convert your BB gun to fire 9mm rounds!

You do realise that this can be done to certain models? Here are some links :)

http://www.telegraph.co.uk/news/main.jhtml?xml=/ne ws/2003/01/05/ngun105.xml [telegraph.co.uk]
http://www.criminal-information-agency.com/firearm s_record.php?id=8 [criminal-i...agency.com]

Re:Why use a BB gun?

FOURTH SAFETY WARNING: YOU COULD EVEN YOUR EYE OUT DOING THIS!

So it's a cure for being crosseyed? Someone get Navin R. Johnson on the phone!

Re:Dangerous

No problem. He just need to wait until a reply gets modded up +5 Informative. That's a sure way to guarantee that anything posted on Slashdot will be accurate, with correct precision, and not be filled with crackpot theories, right?

Re:Dangerous

All you have to do is watch it through a fish tank. If a beam comes back at you, it would just difuse or refract in the watter. There is a bonus if it hits the fish.

Re:Dangerous

CD burners are 780-800 nm, in the IR. DVD's are 660, in the red. Blu-Ray are 405 nm, in the deep blue range. For CD and Blu-ray, welding goggles with a #5 shade would be adequate (complete IR and 10,000x visible attenuation) but for this laser you'd want something that had an OD of more like 7-10 in the red range. A good pair of glasses intended for helium-neon lasers or ruby lasers would probably work, but there are safety glasses intended specifically for these diodes, supplied to people who make them. Expect to pay about $350+ new, but ebay has laser safety goggles for cheaper. But get the technical specs on anything you buy used.

Re:Dangerous

The editors cannot change the article as they have killed themselves with their new maglite lasers....

Re:Dangerous

I nearly blinded myself. I work with lasers, and was trying to align one of the mirrors. I misaligned one slightly, causing the beam to shine in my eye. I looked away immediately, but could only see darkness in that eye. I was so shit scared.

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.

Re:Dangerous

this foreign doctor explains to my collegues that she needs to inject a needle in behind the back of my eye.

She takes out her book of english and says slowly "This will..... hurt".

Thank you for giving me tonight's horrible nightmare.

If I wet the bed, I'm sending you the laundry bill.

Re:Dangerous

Oh yeah? How much does it cost to hang the sheets out on the line to dry?

Re:Dangerous

Your idea of cleaning piss stains off of sheets is hanging the sheets out to dry? I think you misunderstood what your mom meant when she said she liked having crisp sheets on the bed.

Re:Dangerous

If you liked that, here's a charming story from Laser Focus, August 1977.

When the beam struck my eye I heard a distinct popping sound, caused by a laser-induced explosion at the back of my eyeball. My vision was obscured almost immediately by streams of blood floating in the vitreous humor, and by what appeared to be particulate matter suspended in the vitreous humor. It was like viewing the world through a round fishbowl full of glycerol into which a quart of blood and a handful of black pepper have been partially mixed. There was local pain within a few minutes of the accident, but it did not become excruciating. The most immediate response after such an accident is horror. As a Vietnam War Veteran, I have seen terrible scenes of human carnage, but none affected me more than viewing the world through my bloodfilled eyeball. In the aftermath of the accident I went into shock, as is typical in personal injury accidents.

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.

This was caused by a reflection from an infrared laser beam of fairly low power (a 10 ns pulse totalling 6 millijoules). Note that the researcher wasn't actually looking directly at the reflection... the reflected beam was just in his field of vision and directed toward one of his eyes. So for those people who think 'not looking at the beam' is an adequate safety procedure... it isn't.

Re:Dangerous

For what it's worth, my laser was 30nm pulse of about 3 mJ at 440nm (blue).

Re:Dangerous

My contact lenses block the government mind control frequency being sent through the television.

Re:MOMMY!

It's important to be made aware of the mind control tactics used by our government. The only problem I've had with them is that I'm not sure if the contact lenses work or not.

That's why you should just stick with tin foil. Everyone knows that works. Believe me, if the government mind control was working on me, I'd know about it! But I have to go now -- I like to get my quarterly estimated income taxes paid nice and early.

Re:Dangerous

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

Pussy.

I've got one sitting right here on my desk, and I can shine it in to my eyes with absolutely no problems. Allow me to demonstrate...

Srr?

Sbao;utelu ni orpbkens,

Re:Dangerous

This is a very dangerous toy

IT WILL BLIND YOU IMMEDIATELY

Humbug! All my life they have been telling me masturbation does the same exact thing.

Re:Dangerous

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.

Yes, but on the bright side the eye patches will help identify the willing-to-do-anything children at a distance, and we need more pirates anyway.

- RG>

Re:Dangerous

I think the point here is that a little itty bitty laser diode doesn't seem intrinsically dangerous to a lot of people. A knife, for some reason, is easier to understand that it can and will cut you if it is mishandled. But a little self-education on the dangers of a knife generally doesn't result in blindness.

The only saving grace in this article and video is that the beam will hopefully not be that well collimated over a longer distance and when idiots shine it at other people, the damage will be less and the people will have time to look away before they get serious damage.

Also, a laser like this would probably leave lines or dots burned into the retina. It isn't as bad as a pulsed laser that can literally rip the retina off the back wall of the eye because of what are essentially sonic booms in the eye due to the fast rise times and heating pulses. But if it can burn a hole in a piece of paper, imagine what it can do to all your rods and cones when your eye focusses the beam into an even smaller and more intense spot in your eye.

I agree with all the other posters who say the video should be removed and that this article should be pulled.

Re:Dangerous

I agree with all the other posters who say the video should be removed and that this article should be pulled.

I was with you all the way on your comment until you said that.

Removing the article (or the video) won't make this go away, a clear warning however might at least stop some people from getting hurt.

Re:Dangerous

It's not so much the idiots blinding themselves, as a previous poster pointed out. It's them blinding everyone else around them that's more worrying. You know, the ones that bring laser points to movie theaters? One malicious person could go to the front and start randomly shining it over the crowd.

Re:Uhhh...

How funny, I was reading this post and happened to see this at exactly the same time:

"Bureaucrat Conrad, you are technically correct. The best kind of correct." [imdb.com]

Re:Uhhh...

Yeah, but now you can put it on sharks!

Sounds like fun.

Know what I'm doing this weekend :) now if only this could be modified for Laser tag

Re:Sounds like fun.

Just tape balloons to people in strategic spots, I guess.

This is cool, but can it...

actually ignite a match like that? I didn't know that 2 AA batteries could put out that much power in a laser beam... this is clearly a lot more powerful than your standard run-of-the-mill laser pointer used in presentations. I'm so tempted on doing this.

Cool isn't the word...

The problem isn't the current draw - it is the heat. The big laser pointers tend to ensure there is better thermal coupling to the case so the waste heat is removed. With this, it will tend to heat up the module until pssst... and your laser is dead. Should be ok for less than a minute or so.

Re:Sure

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.

Re:Sure

As I said in another post, DVD burning uses lasers rated for over 200 mW. You can buy a DVD burner for under $40 and strip out the laser, or you can often buy replacement/repair carriages for burners on ebay for even less.

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.

Great...

Now when I go to the movies, instead of worrying about Brad Pitt having a red dot on his face, I have to worry about the screen igniting. Good times.

Re:Great...

You know they're gonna solve that before we have kids.

Tiny Violin: Poor kids never know the simple pleasure of the laser :(

Re:Great...

You know they're gonna solve that before we have kids.

At /. it's like saying "You've got a better chance winning the lottery though..."

Careful with this thing.

In the words of Rainier Wolfcastle:

My eyes! The goggles do nothing!

yeah baby

So where did I put those frikin sharks?

Shark

Ok, so where do I get the shark ? and where is the manual on how to mount it on the shark ?

Re:Shark

and where is the manual on how to mount it on the shark ?

Mounting the laser could be a slight problem if the shark is conscious

Re:Shark

Mounting the laser could be a slight problem if the shark is conscious

Just turn the shark upside down before mounting, that makes it go into tonic immobility for about 20 minutes.

Re:Shark

Ew! Ick! TMI man, TMI.

Re:Shark

Turning the shark upside down could be a slight problem if the shark in conscious

Re:Shark

Just turn the shark upside down before turning it upside down, that makes it go into tonic immobility for about 20 minutes.

Re:Shark

and where is the manual on how to mount it on the shark ?

mount -t lamniformesh /dev/laser shark

To repeat an old warning

"Do not look into Laser with remaining eye!"

Re:To repeat an old warning

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.

Re:To repeat an old warning

The difference is that most people know that pins and eyes don't mix. Numbtards don't run around with consumer grade pins and stick them in peoples eyes, but they don't think twice about fooling around with laser pointers.

The legal power limit on laser pointers is set so that they eye's natural blink reflex will protect the retina from permanent damage. This thing is 50 * the limit, and will cause permanent damage at less than 1/100 second. Blink reflex is at about 1/10 second. Even partial reflection off something like a milk glass might cause permanent blind spots (and you are unlikely to realize it at the time, the brain interpolates). An instructable like this without a warning to use laser safety glasses and treat it like you would a .22 gun is an accident waiting to happen.

Also, if you use a diode rated at say 200mW@2.5V it will output a lot more if run at 3V. And someone is bound to make one with a CD-burner diode; while they are lower powered, they output IR so you won't see where you're pointing it and it won't trigger the blink reflex.

This is why I read Slashdot

Windows bashing? Witty comments? Duped stories? Comments about duped stories and how often they get posted? Soviet Russia and Overlord jokes? Left-leaning political commentary?

Nope. None of those things.

Articles about making lasers? Yes! Yes! It can light things on fire too?

Excuse me. I think I may have just wet my pants.

Re:This is why I read Slashdot

I for one welcome our laser-wielding Soviet Russian overlords with a Beowulf cluster of goggles that do nothing against Natalie Portman covered in hot grits making the first post on a duped story about the Cowboy Neal option for polls.

Re:This is why I read Slashdot

overlords running Linux on a Beowulf cluster...

At least be complete, you insensitive clod.

Re:This makes me sad.

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.

Good plan

There's going to be a lot of blind hackers in the next couple of weeks. If you're smart, you'll figure out how to wrangle this as workmans comp before you build the thing.

Re:Nice timing

would other speed burners still work?

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).

Re:Nice timing

In all probability, the batteries will probably limit the current all by themselves - AA batteries typically are fairly high impedance sources and just can't deliver an awful lot of current. I have high power LEDs without much in the way of current limiting because the impedance of the battery (plus the Rds(on) of the MOSFET that turns them on) is such that the current is a little less than nominal (300mA rather than 315mA, with an absolute max. of 550mA).

Young Skywalker

I see you have constructed a new lightsaber. Your skills are complete, indeed you are powerful as the emperor has foreseen. - Darth Vader

Soddering?

Is that a strange way of pronouncing 'soldering'?

Re:Soddering?

It's an American thing. The rest of the English speaking world uses 'soldering'.

BluRay

Think of (all?) the people who now have a good use for their BluRay players. ;P

Um, *excuse* me!?

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!

Re:Um, *excuse* me!?

You're not the boss of me. I hate you! I hate you! God, my family sucks.

Oh, sorry. I was channeling a 14 year old emo girl for a minute.

Dumbass in the comments

There is a guy in the comments section of the blog who is giving out dangerous advice:

That thing might blind you if you stare at it but second or 2 blast won't do any damage. It took a bit to pop the balloon and your eyes are probably tougher than a balloon.

That is so completely false.

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:Dumbass in the comments

The laser used in the article is said to be 245mW, so with regards to eye safety it would not be an exaggeration to say 'this is a weapon, not a toy'.

I know about dead optic nerves

[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.)

This stuff is fun. . .

. . .but read and understand the safety FAQ first:

http://www.laserfaq.org/sam/lasersaf.htm#safssl2 [laserfaq.org]

Torben

MY EYES!

MY EYES! The googles do nothing!

Umm, this isn't a toy..

It's a personal Protective device. I, for one, plan on keeping this handy or even making it find a home in a smaller case that can run on button cells (if only for a few seconds) purely as a protective device.

Pepper spray? My balls! Nothing to teach an assailant a lesson like losing vision in one eye.

actually the one thing I am VERY interested in is if can produce enough pinpoint heat to start a flammable liquid on fire from a distance...oh.. I think I just came.

As much as I hate lawuits...

I seriously hope someone sues the fuck out of this guy SO badly that he'll never be able to afford a flashlight or a DVD burner again.

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.

Re:As much as I hate lawuits...

So? By the time I was 13 I could build so many different kinds of bombs out of things you can get out of the hardware store that I should have been called a terrorist by today's standards. Here's one for you, know what happens when you mix acetylene with oil? No? Try it sometime pretty fun if you ask me also extremely deadly, there's a reason that acetylene bottles say not to oil the threads of the valve cap. There are so many much worse things that you could do that are well documented on the internet now that I didn't have access to, I actually had to work at stuff like this but these days you don't it's all there for the taking. So really this is pretty small potatoes and you're just having a knee jerk reaction like so many people do. You want to know what was the key instrument of me not hurting myself or others when I started to get really interested in blowing shit up? My father quickly realized that I was going to find a way to do it one way or the other so he taught me the safe way to do it, the same can be applied to lasers. Kids need to be allowed to experiment with stuff that's how you learn and better yourself, keeping kids and teenagers locked up in an iron box and not letting them do dangerous things that are also very educational just churns out the next generation of factory workers. For instance my fascination with explosives led me to make my own brand of rocket fuel, then that led me to want to make a rocket. Since I wanted to make a rocket I learned about CAD and Drafting then made drawings and took them to a machine shop to make said rocket. I launched and guess what? It flew! Amazing! Look at all that I learned along the way! Now take a laser for instance, imagine if a kid saw this and realized that he could do a little engraving with something like this. It may eventually lead him to FAB@home and maybe just maybe he/she would build on of these machines, imagine what they would learn along the way. It's attitudes like yours that stifle the creativity and imagination of future generations. Knee-jerk reactions like ZOMG! teh t'rrists can blind someone serve no one only breed the already stifling culture of fear that we live in now. This could be a great teaching tool, it's fun, cool, and has visible results as well as being inexpensive. I think all physics classes in school should be encouraged to have students build things like this, it leads to interest in the subject and you know what that makes? Wow! You guessed it, a smarted more creative generation of forward thinkers. I could go on for hours but I'm going to quit now before I get all worked up.

Blinding lasers are banned.

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 [wikipedia.org].

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.

Meanwhile, back at the White House, a plan develop

Bush: We've go to do something to get rid of all those dangerous hackers.

Vader: Perhaps we could post a video showing them how to make a dangerous weapon that they would accidentally use on themselves.

Jobs: Hmmm... there's a dangerous laser in DVD burners.

Gates: Yeah, let's hope that works better than your plan to make them all deaf with your stupid iPod, or get them run over walking across the street, playing with their iPhone.

Laser diode may not last too long run like this...

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.

Laser Safety, Standard Operating Procedures, Gear

Please mod this 5 and tack it up towards the top someone.

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.

Re:Laser Safety, Standard Operating Procedures, Ge

The optical DRIVE is class I, because it's enclosed by a metal box and has interlocks, thus posing no danger if operated normally. The diode inside can be class II, III, IV, or whatever. Every DVD drive would have similar power output, since that's what it takes to burn DVDs.

Eye protection

A lot of people here have mentioned how dangerous this laser is in terms of the ability to fry eyes and/or cause blindness. Is there anyone here who can indicate what the proper safety gear would be when dealing with lasers of this variety? I'm guessing that anti-UV sun-glasses aren't quite good enough... and welders goggles perhaps a bit too dark to accomplish any work?

Looks like lots of fun - but

Please - if you build one of these you need to be aware of the EXTREME DANGER involved in playing with this little toy.

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.

Re:Laser Housing

"Is that necessary? Is it just a metal tube or does it serve a more substantial purpose."

Yes.

Now do you understand why they don't allow optical media writers in your carry-ons?

Next week...how to turn a laser into a repeating rifle - all part of our DIY Firearms Convergence Series, here on the 'Defending the Homefront' Channel. Brought to you by 'Ahmed's Security Stuff' - at ASS, we pick up on the first ring!

Re:Mods, wake up!

No. Decidedly, no. Information has never and will never cause harm. It cannot. I do agree that some information, like certain pictures, can cause bodily harm because they induce the reproduction of your last meal, but you're free to ignore said information and keep your ham and eggs with you.

If someone is dumb enough to use the information and blinds himself, he's the only one to blame for it. That something like this is harmful should be obvious. If it's not, this is due to the person having not enough information on the subject to see the problem.

Re:Mods, wake up!

Information can most certainly cause harm when it is incomplete. This video makes it look like harmless fun - hey, kids, take apart your DVD burner and pop a balloon! Not one mention that you should be wearing goggles, that even partial reflections can blind you or others. Using this thing anywhere except a windowless room where everyone inside the room is in protective eyewear is irresponsible and dangerous.

Teaching someone how to make a tool without also showing them how to use it properly is irresponsible, especially if you neglect to even tell the person that the tool is very dangerous. I think you are right in that anyone stupid enough to look into the beam deserves to be blinded, but this thing will also blind anyone who's exposure to the beam is less than 1 ms - shorter than the blinking reflex. Even a 10% reflection is more powerful than a some laser pointers. Common sense may keep you from staring into it, but it might not occur to you just how dangerous it is.

Re:Laser Housing

Re: Is the metal housing really necessary? ....Yes, for the most part.

I tried this some time back, and it didn't quite work, but I'll relate what I know anyway:

1. There's TWO laser diodes in a DVD burner--remove them both out carefully, preserving as much of the leads already-soldered-on as you can! The leads of the laser diodes are very short (maybe 2mm) and only about a half-millimeter apart, it's damn tough to get the longer leads soldered back on if you cut them off, and there's no need to cut them off and then attempt to solder them back on anyway.

2. Inside the DVD burner you will find TWO laser diodes, with mirrors that feed them both into the same beam. Each will be glued inside its own heatsink, a piece of metal that may be a very odd shape, and then these are attached to a bigger copper plate. To tell them apart, just test them--try applying 1.5V power to both diodes one at a time, the CD one is IR and won't appear to do anything. The DVD one will light up visible red. (if all the lenses are removed from them at this point, you cannot burn your eyes out, that's in the next step...)

3. The bare laser diodes don't put out a laser "beam", they just create a pinpoint light (that's safe to look at!). To get the beam, you must mount a fisheye lens with its concave side set very close to the diode, almost touching it.

4. The laser housing is a metal tube with a fisheye lense set in it. The laser diode will get warm with 1.5V on it, and will get too hot to hold in ~30 seconds with 3V on it. The laser housing serves partly as a heatsink, and also as a way to hold the lens without melting (the DVD-drive optics will have a fisheye lense, but those optics are usually set into little plastic frames, and they may melt in this use).

....Mine didn't work because I could not find a way to get the laser diode out of the original steel heatsink it came in. It was glued inside a hole about 6mm deep in a odd-shaped steel heatsink. You could maybe grind the heatsink away a bit at a time with a Dremel & cutoff wheel, but laser diodes are sensitive to heat, so you cant let the laser get too hot. I tried using mine still in its heatsink with other optics (telescope objectives and whatnot), and with those set in front of it, it would melt a garbage bag a little but wouldn't do much else.

IF you manage to get one out and do this, don't run it for more than ~20 seconds at a time without letting it cool down for a minute or so. The laser diode will work with 3V batteries hooked straight to it, but you're definitely not going to get that 100,000 hour lifetime. You'd be lucky to get 1000 hours. The DVD laser output power is typically around 210mW, and more than 150mW is enough to burn stuff (the CD laser won't burn stuff because it's only around 40-50mW max).
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