Physicists said Tuesday that a so-called optical lattice clock, touted by some as the time-measuring device of the future, had passed a key accuracy test.
The performance boosts chances that the world’s timekeepers will one day adopt it for defining the second, they said.
The atomic clock, introduced in 1955, measures time by using microwaves to probe atoms as they transit between two energy levels.
The high accuracy of these clocks lies behind the success of the Global Positioning System (GPS), which requires orbiting satellites to be synchronised so that their signals, received on Earth’s surface, can be triangulated to give the receiver’s location.
Impressive as these clocks are, they can—in theory—be outperformed by lasers.
This is because the “tick” of an atomic pendulum is in fact something that occurs trillions of times every second… if you can measure it.
Microwave radiation operates at a frequency of about 10 Gigahertz, whereas that of a laser beam is 40,000 times higher.
As a result, a laser can dissect the “tick” into many more time intervals than a standard atomic caesium clock, and offer higher accuracy.
In a study published in Nature Communications, a team led by Jerome Lodewyck of the Paris Observatory describe the performance of an optical lattice clock, in which about 10,000 atoms of the radioactive element strontium were trapped and measured by laser light.
Read more at: Phys.org