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Diamond Design Proves Concept of a “Death Star” Laser

Researchers at Macquarie University have proven a method for multiplying laser power using diamond, demonstrating that the “superlaser” employed by the Death Star in Star Wars may not remain in the realm of science fiction.

The research, published in Laser and Photonics Reviews, demonstrates a concept where the power of many laser beams is transferred into a single intense output beam that can be directed at a target.

High-power lasers are already being investigated in areas such as defence. “Researchers are developing high-power lasers to combat threats to security from the increased proliferation of low-cost drones and missile technology,” said co-author A/Prof Rich 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 key to the high-powered beam is placing an ultra-pure diamond crystal at the point of convergence. The laser beams can then be combined in the diamond by harnessing a cooperative effect of the crystal that causes intense light beams to transfer their power into a selected direction while avoiding the beam distortion problems of single laser technologies.

“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, and combining beams from multiple lasers is one of the most promising ways to substantially raise the power barrier,” said lead experimentalist Dr Aaron McKay.

While other methods of combining laser beams are being trialled elsewhere in the world, beam combining in diamond has the unique advantage of changing the colour of the laser beam. “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,” Mildren said.

Although other materials have exhibited beam-combining properties, the power-transfer effect at the heart of the device, called Raman scattering, is particularly strong in diamond, which is also outstanding for its ability to dissipate waste heat rapidly.