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The super laser made popular in the Star Wars movies may soon be more than a feature in a popular film series.

Researchers from Macquarie University in Australia have developed a method for multiplying laser power using a diamond, where the power of multi laser beams is transferred into a single intense output beam that can be directed to the intended target.

The new laser development has several real-world and high-stakes applications where high power lasers are seen as a crucial tool, such as in defense.

“Researchers are developing high power lasers to combat threats to security from the increased proliferation of low-cost drones and missile technology,” associate professor Rich Mildren, the co-author of the study, said in a statement. “High power lasers are also needed in space applications including powering space vehicles and tackling the growing space junk problem that threatens satellites.”

An ultra-pure diamond crystal is placed at the point of convergence and the beam combining is achieved in the diamond by harnessing a co-operative effect of the crystal that causes intense light beams to transfer their power into a selection 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,” lead experimentalist Aaron McKay, Ph.D., said in a statement.

While other materials have exhibited the same type of beam combining properties, the choice of diamond is necessary for high power. The power-transfer effect at the heart of the device—called Raman scattering—is particularly strong in diamond.

In addition, diamonds have the ability to rapidly dissipate waste heat.

According to the study, power from multiple non-collinear pump beams is efficiently transferred onto a single Stokes beam in a single-pass amplifier. Using three mutually-independent nanosecond pulsed beams from a free-running-linewidth 1064 nm laser, 69 percent of the total peak pump power of 6.7 kW was transferred onto a TEM₀₀ Stokes seed pulse at 1240 nm in a 9.5 long diamond crystal.

Diamond beam combing is an alternative to other concepts being currently trialed elsewhere in the world.

In this study, beam combining in diamond has the advantage that the process also changes the color 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.

The study was published in Laser & Photonics Reviews.

 

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