CIFS - Calcium Ion Frequency Standard

Highly accurate atomic clocks have a broad and expanding range of vital applications and are used in many aspects of our daily lives. One well-known example is the GPS navigation system which depends on sub-microsecond accurate timing to provide both position and timing information. This information is used in communications systems, telecoms, finance and infrastructure applications, as well as a host of other less obvious places.

However, satellite-based systems are vulnerable to external influence and attack. Consequently, many of these dependencies are now exposed, and action is required to make systems that depend on satellite-derived timing information more independent and robust.

Timing systems based on trapped ions can deliver significantly improved accuracy over currently available commercial systems. Clocks based on trapped ions will enable both backup and stand-alone systems to be built. Currently, these systems, which give accuracies of 10^-18, similar to an error of one second in the age of the universe, have only been demonstrated in research labs.

Furthermore, due to their complexity, power consumption and environmental requirements, these systems are far from portable as well as being too expensive for widespread deployment.

The University of Sussex has developed a portable optical atomic reference based on trapped calcium ions probed by a "clock" laser pre-stabilised to a compact optical cavity and, in conjunction with an optical micro-comb, can turn the output of the system into a useable signal. Together these systems function as an atomic clock with the accuracy required to support future communications and infrastructure systems.

This project aims to improve and industrialise the current calcium ion clock design, reducing the size and weight of the system and ruggedise it by increasing subsystem integration. This will make it a much more useable product for many systems and should open up a new market for advanced timing devices with a wide range of applications.

A portable optical atomic clock system will be developed, and its integration in various applications explored with the combined efforts of the consortium, which comprises of:

* TMD Technologies, a leading company in quantum technology development, vacuum electronics and ruggedised electronics for defence applications; * Covesion, experts in nonlinear optics and optical system development; * Chronos Technology, a leader in timing and synchronisation equipment; and the University of Sussex,

* Leonardo, a leading system integrator; * BT, a communications services provider focusing on high-speed optical networking technology; * QinetiQ, a science and engineering company operating in the defence sector.