Star Wars superlaser steps out of sci-fi

Macquarie University researchers have proven a method for multiplying laser power using diamond, demonstrating that the superlaser from film franchise Star Wars may not remain in the realm of science fiction for much longer.

The superlaser in Star Wars — the primary weapon of the Death Star battle stations — was powered by eight kyber crystals. Laser beams generated from these crystals were focused and combined into a single blast, which was capable of destroying an entire planet at full output.

Similarly, the Macquarie University researchers demonstrate a concept where the power of multiple laser beams is transferred into a single intense output beam that can be directed to the intended target. Their study has been published in the journal Laser and Photonics Reviews.

“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.

The key to the high-powered beam is placing an ultrapure diamond crystal at the point of convergence. The beam-combining is achieved in 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. The process also changes 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,” said study co-author Associate Professor Rich Mildren.

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

The new laser development has real-world and high-stakes applications, with high-power lasers seen as a key tool in areas such as defence. Associate Professor Mildren added that such a laser may also be useful in space applications, including powering space vehicles and tackling the growing space junk problem that threatens satellites.