The device, dubbed an optical lattice clock, loses just one second every 300 million years, making it three times as accurate as current atomic clocks, the BBC reported Wednesday.
The first atomic clocks, keeping time using the very regular vibrations of atoms, proved to be the most accurate method yet and since the 1960s has been used to define a second in the International System of Units.
Current atomic clocks expose clouds of cesium atoms to microwaves to get them to oscillate or vibrate, but the new clock, developed at the Paris Observatory, uses laser light to cause the same effect in strontium atoms.
"In our clocks we use laser beams," Jerome Lodewyck of the observatory said. "Laser beams oscillate much faster than microwave radiation, and in a sense we divide time in much shorter intervals so we can measure time more precisely."
Telecommunications, satellite navigation and world stock markets rely on ever-more precise time measurements, the researchers said, suggesting the new clock could one day redefine the second.