DIY

CIRCUITS

MINI HIGH-POWER LASER

Liberate a 200mW laser from a DVD burner.

By Stephanie Maksylewich

High-speed DVD burners are mass-market commodities now. Most new computers sport DVD±RW drives, and discount shops sometimes carry upgrade burners for less than $30. They’re cheap, but inside every one lies a hidden secret that many of us would have killed for 20 years ago: a high-powered, solid-state, visible red laser. This means that with a pretty small expenditure and a little hacking, you can have a portable, handheld laser that’s powerful enough to ignite matches, burst balloons, and melt plastic. Here’s how to do it.

Find a Donor DVD Burner Look for a DVD burner, either single- or dual-layer, that’s rated at 16x or higher. The faster the drive, the stronger its laser diode. The color will be the same regardless — DVD players and burners use a

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red laser at a wavelength of approximately 650nm, which is about the same as most cheap laser pointers.

Don’t try this with a CD burner. These use invisible infrared light (wavelength of 784nm), which will burn your retinas out without you even seeing it. DVD burners also have CD-burning diodes inside, but we’ll ignore them.

If you are looking for something unique, try a violet laser diode from an HD-DVD or Blu-ray drive. These burners are incredibly expensive right now, but they do contain a 405nm diode rated at around 50-60m W. It won’t be able to pop balloons or burn things, but handheld lasers with this color light are rare at the moment. Just be advised that the 405nm diodes take a different voltage from the diode we’ll be working with (5V DC rather than 3. 3), so you’ll need a different circuit.

Photograph by Sam Murphy