Ultra-precise, Shock-resistant Optical Clocks (USOC)
Lead Research Organisation:
IMPERIAL COLLEGE LONDON
Department Name: Physics
Abstract
Precise timing and synchronisation systems have a remarkable impact on our lives. Behind the scenes, precise timing underpins our digital communication networks, radar systems, and global satellite navigation systems (GNSS) such as GPS. The exceptionally precise timing offered by atomic clocks has been essential for these elements of our national and international infrastructure for several decades.
While traditional microwave atomic clocks already have impressive precision down to 1 part in 10^14, atomic clock technology has undergone a revolution in the past two decades, since the invention of a new, accurate method to measure optical frequencies (see 2005 Nobel Prize in physics). Using the new `optical' atomic clocks, it is now possible to measure time more precisely than ever, with uncertainty down to a few parts in 10^19. These optical clocks have exciting applications in fundamental science: for example, we can observe them ticking at different rates when they are changed in height by as little as 1 mm from the ground, due to subtle effects of general relativity. However, if optical clocks could be deployed outside the laboratory, they could also have a significant practical impact on our lives - for example, they could enhance the speed and resilience of our digital communication networks.
In this project, we are developing a new type of optical atomic clock which can not only measure time with even greater precision than current laboratory optical clocks, but will be robust enough to leave the laboratory and be deployed in field applications such as communication networks. At the core of our clock, we stabilise the optical ``ticks'' to the atoms continuously, rather than using more traditional pulsed stabilisation techniques. This continuous stabilisation improves the precision of the clock at short measurement times by a factor of up to 100, and greatly reduces sensitivity to mechanical shocks - which is otherwise an insurmountable barrier to developing portable, deployable clocks.
While traditional microwave atomic clocks already have impressive precision down to 1 part in 10^14, atomic clock technology has undergone a revolution in the past two decades, since the invention of a new, accurate method to measure optical frequencies (see 2005 Nobel Prize in physics). Using the new `optical' atomic clocks, it is now possible to measure time more precisely than ever, with uncertainty down to a few parts in 10^19. These optical clocks have exciting applications in fundamental science: for example, we can observe them ticking at different rates when they are changed in height by as little as 1 mm from the ground, due to subtle effects of general relativity. However, if optical clocks could be deployed outside the laboratory, they could also have a significant practical impact on our lives - for example, they could enhance the speed and resilience of our digital communication networks.
In this project, we are developing a new type of optical atomic clock which can not only measure time with even greater precision than current laboratory optical clocks, but will be robust enough to leave the laboratory and be deployed in field applications such as communication networks. At the core of our clock, we stabilise the optical ``ticks'' to the atoms continuously, rather than using more traditional pulsed stabilisation techniques. This continuous stabilisation improves the precision of the clock at short measurement times by a factor of up to 100, and greatly reduces sensitivity to mechanical shocks - which is otherwise an insurmountable barrier to developing portable, deployable clocks.
Publications
Elder B
(2025)
Prospects for detecting new dark physics with the next generation of atomic clocks
in Physical Review D
| Description | The award aimed to demonstrate key technologies behind a new generation of Ultra-stable Shock-resistant Optical Clocks, by demonstrating for the first time a continuously-probed optical clock. The technical objectives were: 1. High-flux sources of cold Sr and Yb atoms 2. Continuous laser cooling of Sr and Yb 3. Compact Sr and Yb clock clocks 4. Continuous stabilisation to the "clock" transition in Sr and Yb Objective (1) was achieved very successfully - we built the world's highest flux Sr atom source. A publication has been prepared but not yet submitted. Objective (2) was partially achieved, and still in progress. Follow-on funding has been applied for, to finish this work in both Sr and Yb systems at Imperial and NPL Objective (3) was partially achieved, with initial demonstration of Yb atoms in a very compact source at NPL Objective (4) was theoretically investigated, and we are currently preparing a publication on very promising experimental configurations for both Sr and Yb |
| Exploitation Route | The high-flux Sr source is being published with open access to the design, with prospects for wide adoption by the quantum researchers in academia and in startups (especially quantum computing companies) The continuous clock stabilisation scheme, once published, is likely to be adopted by academic groups to make the most stable clocks for the SI second and for commercial applications (geodesy, inertial navigation) |
| Sectors | Aerospace Defence and Marine Digital/Communication/Information Technologies (including Software) Transport |
| Description | "Time" online workshop for kids |
| Form Of Engagement Activity | Participation in an activity, workshop or similar |
| Part Of Official Scheme? | No |
| Geographic Reach | Regional |
| Primary Audience | Schools |
| Results and Impact | 80 pupils (yrs 5 and 6) from four schools joined for four Zoom sessions for one hour each, to learn about the "time" in physics. They were shown around the USOC atomic clock laboratory, and showed them how only balloons of a specific colour would "pop" when we blasted them with a laser - an analogy for how atomic clocks only resonate when blasted with the right wavelength of laser. |
| Year(s) Of Engagement Activity | 2024 |