UNIVERSITY scientists have developed a system which could help astronomers find Earth-like planets – and it is powered by a laser similar to those sold in shops for a few pounds.
Researchers at Edinburgh’s Heriot-Watt University have produced a device powered by a green laser similar to laser pointers sold for less than £5. But it emits light at one billion pulses a second, helping to produce what is known as a frequency comb.
Professor Derryck Reid, head of the ultrafast optics group at Heriot-Watt, said the laser has huge potential to enable astronomers to detect small Earth-like planets orbiting distant stars.
The university says the laser reduces the cost, complexity and power consumption of typical ultrafast lasers by around a factor of 10.
The breakthrough is reported in the journal Optics Express.
Reid believes it could help astronomers searching for exoplanets, planets which revolve around stars outside of the Earth’s solar system.
Using space telescopes, astronomers have identified thousands of stars that might have exoplanets but each of these must be confirmed by ground-based telescopes looking for tiny fluctuations in the colour of the star’s light.
“These tiny wavelength shifts confirm the presence of an orbiting planet and provide
its mass and orbital period,” Reid said. “Our new laser is a smaller and simpler version of one we installed on the 10-metre Southern African Large Telescope in 2016.
“The laser produces light consisting of thousands of regularly spaced optical frequencies, known as a frequency comb. Much like a ruler is used to accurately measure distances, it allows astronomers to measure exact wavelength differences.
Heriot-Watt PhD student Hanna Ostapenko came up with the design for the system.
She said: “What’s unique about this laser is we’ve shown we can power it from a simple laser diode with about the same energy consumption as an iPhone. Unlike many previous ultrafast lasers, ours contains very few components and produces ultrafast pulses as soon as it powers up.”
