The Death Star's laser may no longer be science fiction

The massive laser weapon that blows up Alderaan in Star Wars Episode IV: A New Hope would require a lot of energy. A while back, here on TechRadar, we wrote a feature about how to build a real-life Death Star, and in it we quoted a research paper that calculated exactly how much energy you'd need to blow up the Earth.

The answer: 225,000,000,000,000,000,000,000,000,000,000 joules of energy. Jupiter? Try 10,000 times that amount. It's probably for the best that we've got no technology that can deliver anything close to that level of power in a single laser beam.

But, perhaps worryingly, we're getting closer. Optical engineers at Macquarie University have developed a method for multiplying laser power using exceptionally pure crystals of diamond, where the power of several beams are combined into a single intense output beam.

Raise the power barrier

"This discovery is technologically important as laser researchers are struggling with increasing power beyond a certain level due to the large challenges in handling the large heat build-up," said lead experimentalist Aaron McKay. 

"Combining beams from multiple lasers is one of the most promising ways to substantially raise the power barrier."

Diamonds are particularly good for this process because the power-transfer mechanism, called Raman scattering, is particularly strong in the material. The crystal allows light beams to transfer their power into one direction while avoiding beam distortion. It's also able to rapidly dissipate waste heat, and can even change the laser's wavelength.

"The particular wavelength of the directed energy beam is critical to the efficient transmission through the atmosphere and to reduce the eye hazard for people, or indeed animals, who may be in the vicinity of the beam," said co-author Rich Mildren.

Real-world applications

As well as serving as an encouragement to any wannabe Sith lords out there, the team says that the development has real-world applications.

"Researchers are developing high-power lasers to combat threats to security from the increased proliferation of low-cost drones and missile technology," said Mildren. 

"High-power lasers are also needed in space applications including powering space vehicles and tackling the growing space junk problem that threatens satellites."

The full details of the research were published in the journal Laser & Photonics Reviews.

Duncan Geere
Duncan Geere is TechRadar's science writer. Every day he finds the most interesting science news and explains why you should care. You can read more of his stories here, and you can find him on Twitter under the handle @duncangeere.