Researchers reveal world's most precise metronome

Scientists in Germany have synchronized a system of lasers with record precision. The metronome’s laser-microwave network stretches a kilometer wide, or 3,280 feet, and is synched within 950 attoseconds.

One attosecond is a millionth of a millionth of a millionth of a second, or a quintillionth of a second. One femtosecond is a quadrillionth of a second, or a millionth of one billionth.

“Extreme timing accuracy is important for many areas of research,” Kemal Safak, a PhD student and researcher at the Center for Free-Electron Laser Science, said in a news release. “For instance, challenging geodesy tasks require signal synchronization with picosecond precision, which is a trillionth of a second. High-precision navigation and multi-telescope arrays for astronomy need even a higher precision of up to 40 femtoseconds.”

The X-ray free-electron laser FLASH, located at the German Electron Synchrotron, or DESY, already boasts a precision of 30 femtoseconds. It is used to image biological, chemical and physical reactions at nano timescales. The first pulse of a laser triggers a reaction, and the next pulse, after a specified time gap, images the reaction. By slowly expanding the time gap, the system can create a stop-motion film of the reaction.

“If we can achieve even better precision, this would promise radically new science by shedding light on molecular and atomic processes happening on the attosecond timescale,” explained lead researcher Franz X. Kartner, a professor at the CFEL.

The latest efforts don’t simply synch two lasers, but an entire system of lasers, propagating ultralow-noise pulse using a mode-locked laser as a timing mechanism. The pulses are distributed through stabilized fiber-optic links.

“The attosecond-precision laser-microwave network will enable next-generation XFELs [X-ray free-electron lasers] and other scientific facilities to operate with unprecedented timing accuracy, helping them to unfold their full potential,” said Kartner. “This will drive new scientific efforts towards the making of atomic and molecular movies at the attosecond timescale, thereby opening up many new research areas in biology, drug development, chemistry, fundamental physics and material science.”