Decades after its birth, the laser is still irresistibly cool. How many other fifty-somethings can you say that about? See Also: This Day in Tech

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Happy Birthday, Lasers: Wired.com's Best Laser StoriesEven though lasers are as common as dirt now, appearing in everything from DVD players to supermarket scanners to computer mice, there's still a certain appeal to a beam of coherent, monochromatic light. Especially if it's dangerously powerful. So it's no surprise that people can't resist playing with lasers, building their own, customizing them and, of course, setting stuff on fire with them. Theodore Maiman probably never foresaw the ways his creation would be used when he first turned it on in 1960. But then again, he might be happy to know that someone has come up with actual laser rayguns. Above: Pulse Laser Gun Mk II At the top of the do-it-yourself laser pyramid is this amazing pulse gun, capable of pumping out 1 megawatt of coherent light in short pulses. As the video shows, that's enough to punch holes in plastic and, of course, pop balloons. Add a focusing lens and the beam of laser light creates a tiny, intensely hot ball of plasma that can burn holes in aluminum and char wood. It weighs almost 2 pounds, but has a self-contained battery pack capable of 50 shots. It may not be practical as a weapon, but like other powerful lasers, it's very, very dangerous. Photo: Hack N Mod

Altoids-Tin Laser The Altoids tin is a favorite container for DIY projects. It's cheap, easy to work with, compact and looks cool. It makes perfect sense, then, that you'd want to make an Altoids tin that can set things on fire, by bundling a laser and battery pack inside. Even better, this project requires no soldering. All you need is a tin, a 200-mW green laser diode, a switch, a battery pack that holds two AA batteries, some electrical tape, and a startling lack of common sense. http://www.youtube.com/embed/Y7JavGjcb0Y

Bic-Lighter Laser Let's face it: Altoids tins are kind of quaint. Putting a laser in the body of a Bic lighter? Much more macho! You can do it, too, if you can take apart the lighter without setting yourself on fire, hollow it out with a Dremel tool, then stick in a laser-driver module and a blue laser diode. The laser components are both available from LaserDIY.com or Kipkay.com, the source of this video. You'll also need a small 4.3-ohm resistor and a switch. Tear open a 12-volt battery to extract a couple of button cell batteries, cram it all inside the lighter, and there you go. The laser is powerful enough to ignite fireworks or light cigarettes, the video claims. "Of course, as with any laser, never point it at yourself or any living thing," the voiceover helpfully adds, while showing a video of a man aiming the laser at himself to light a cigarette. If you make this project to light your smokes, you may also want to buy an eye patch to cover up your soon-to-be-blinded eye. http://www.youtube.com/embed/5erjj6aS5Ws

Powerful Laser Diode This laser project was obviously created by someone with slightly more common sense, because the video begins with a warning to wear safety goggles. The laser body also has a red status LED on the side, so you can tell if the thing is on without pointing the business end at your eye. The laser has more than 1 watt of power, which is a lot: It's enough to light matches (even from the wood end) cut through black electrical tape, and set paper on fire. Laser Pointer Forums has the details on this project, along with lots of other information on how to take harmless, innocuous laser pointers and turn them into dangerously fun toys. http://www.youtube.com/embed/IJcZKaj93TY

Laser Host Assembly Modern lasers, electrically speaking, are diodes: They are components that allow current to flow in only one direction. They work by converting electricity to coherent light on a specific wavelength. Many "burning lasers" make use of a 1.1-watt laser diode that emits light at the 445-nanometer wavelength. The wavelength makes for a blue light, and the wattage makes for stupid levels of power. (Most cheap laser pointers, by contrast, are less than one-tenth as powerful.) Add a lens and it can be focused tight enough to set things on fire. But you also need something to hold your laser diode and its battery, and that's where this laser host assembly comes in. It's basically everything you need for your overpowered laser pointer, except for the diode, the batteries, and (if you want) a lens. It's $56 at the disturbingly named Survival Laser website. For more background, see this discussion of low-cost 445-nm, 1-watt laser diodes.

Laser Diode From a DVD Burner You don't need to go out and purchase a new laser diode: You can also harvest one from an old optical drive. DVD burners use more powerful lasers than regular CD or DVD drives, and the Lightscribe DVD burners have the most powerful ones, which they presumably use to inscribe lettering on the top surface of the discs. Getting the diode out of a DVD drive can be a tricky process, though. It's easy to bend the connectors, as this hobbyist found out. Photo: Andrew Magill/Flickr

Laser Flashlight-Dazzler Some people are consumed with focusing laser beams into tight spots to set things on fire. This guy went the other direction, diffusing the beam from a green laser pointer so it becomes a powerful flashlight. It now makes a bright, 6-foot-diameter circle of light at 100 yards away. If you were to point that at someone's eyes, it would probably be very disorienting indeed, which is why the maker suggests it could be used as a dazzler weapon. http://www.youtube.com/embed/kEyqUJ3DnBs

Laser Projector Not everyone is using lasers to set things on fire or dazzle midnight intruders. Micah Elizabeth Scott put considerable effort into making a homebrew laser projector that can display vector graphics on the wall. The heart of her system is a 30-mW green laser and two hard-disk motors, which turn mirrors to aim the beam. The result is pretty amazing: It's compact, programmable, bright and has a Bluetooth interface. For details, see Scott's hard-disk laser-scanner project page, and check out her subsequent update. Photo: Micah Elizabeth Scott/Flickr

Laser Engraving System Another ambitious, constructive project: This guy built a homemade laser CNC system from the internals of an old printer, some servos, and an unspecified laser diode. It's controlled by software running on an Ubuntu Linux PC, and can be used for cutting paper for stencils, engraving wood and cardboard, cutting plastic pieces, and engraving printed circuit boards. The project page is skimpy on specifics, but if you're at this level, you can probably figure out the details yourself, right?