May 5th, 2015 | Company News
The frequency comb to find ‘Earth-like’ planets
Hunting for ‘Earth-like’ planets outside of our solar system is becoming ever-more feasible with the investment and developments in frequency comb lasers. The new developments allow for greater precision and more sensitive techniques especially for astronomers investigating stars in other solar systems and the planets orbiting them. Frequency combs work by firing ultra-short pulses (a ten trillionth of a second) of varying outputs, each at a slightly different colour, to create an even comb-like set of frequencies. Frequency combs are highly useful in metrology to create a benchmark for other lasers to calibrate against and it has a highly precise frequency scale. Using a frequency comb, an astronomer can study a star and its slight changes in speed (and alteration of light spectrum) to determine how the star is moving based on the Doppler shift principle. If it is moving away from the observer, it will shift to the red end of the spectrum, if it is moving towards the observer, it will shift to the blue end of the spectrum. The small Doppler shifts for ‘Earth-like’ planets will require accurate measurements, which conventional calibration hasn’t previously achieved. Frequency combs will also be useful in detail observations of the sun or in detecting the presence of hazardous chemicals at a safe distance, a broad base application range.