The accuracy of navigation on Earth is largely attributable to satellite-borne atomic clocks that inform global positioning systems. The potential for downsizing these bulky chronometers for personal or industrial use has Artist’s impression of soliton wave propagation. Source: University of Sussexbeen demonstrated by researchers from the University of Sussex, U.K.

Prospects for a compact, portable atomic clock improve with application of microcavity-based frequency comb technology to realize an 80% efficiency gain in the lancet, the component responsible for counting, analogous to the pendulum in a traditional mechanical clock.

Lancets operate according to the quantum property of a single confined atom, using a device known as an optical frequency comb. This counting element is a laser emitting many colors, equally and precisely separated in frequency, designed to observe the electromagnetic field of a light beam oscillating hundreds of millions of times a second. The researchers encapsulated this function in a compact form by demonstrating microcomb laser cavity-solitons for greater control in microcavities.

Microcombs use optical microresonators to reduce the size of frequency comb equipment. The produced soliton waves, which are resistant to perturbation, emit different colors in the microcavity system, which also assures the robust level of control of larger pulsed lasers.

Realization of a portable atomic clock will have to wait until the new device is integrated with an ultracompact atomic reference. After that, these advanced devices might be found in drones, autonomous vehicles and smartphones.