Improved laser system helps telescopes draw more accurate space data: Aussie researchers

Australian researchers said they have developed an improved laser system that will help large optical telescopes gather more accurate data, offering major applications in optical free-space and ground-to-earth communications, space debris imaging and tracking, and astronomy.

The project involves using precisely tuned lasers to energize atoms in a segment of the Earth’s atmosphere, at an altitude of about 90 km, re-emitting laser light to temporarily create a glowing artificial star, according to a Macquarie University statement late Friday.

Generating specific wavelengths for the process “has been a notorious challenge that has so far needed impractical approaches”, but researchers have shown that their diamond Raman lasers are “a highly efficient way to generate the precise output needed”, the university said.

The findings, reported in scientific journal Optics Letters, showed that “the laser delivered higher power and efficiency than previous guide star laser systems of its type”.

“The applications need brighter guide stars with reduced star elongation and background noise, and these are aspects that our diamond laser approach looks like being able to address,” the project’s lead experimentalist Xuezong Yang said.

“Our approach is also highly practical … as the intrinsic gain properties of the diamond element mean the laser is found to run on a single narrow frequency. This keeps our design simple, and the device potentially robust and low-cost.”

The results are also significant because the technology can be further developed to increase the quality of future guide stars, according to the researchers.

“Diamond can dissipate heat rapidly, and is less prone to unwanted optical distortions. This combination provides a pathway towards producing more powerful guide star beams,” according to the university.

The researchers predict that the extra flexibilities offered, such as delivering the laser power as a series of microsecond optical pulses, will also benefit adaptive optical systems.

Their work “brings forth interesting opportunities to adapt lasers to boost the performance of Earth-to-space adaptive optical systems,” research leader Rich Mildren said.