Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Single-ion traps and cubic cavities for field-deployable laser-cooled optical atomic clocks

Alessio Spampinato, Jonathan Stacey, M. A. Trigatzis, Sean Mulholland, Nathan Vincent, Guilong Huang, G. P. Barwood, Patrick Robert Gill

Published Jun 12, 2026• 0 citations
Publisher

Abstract

Abstract The primary technology for high accuracy position, navigation and timing (PNT) capability worldwide is currently provided by global navigation satellite systems (GNSS). The vulnerability of GNSS to intentional interference, clock component failure or extreme space weather is increasingly pointing to the need for alternative independent navigation and timing solutions to maintain critical national infrastructures, defence, security, commerce and logistics. The availability of low size, weight and power (SWaP) portable atomic clock technology with resilience and extended holdover times for use both in space and terrestrially is now increasingly urgent. In this paper, we report on progress in the development of compact optical clocks that offer the capability to out-perform existing commercial microwave atomic clock systems. We discuss designs for a compact transportable cold trapped strontium ion optical clock with both a low SWaP design and high accuracy that can address extended holdover for future navigation and timing requirements. We describe how key sub-systems of an optical atomic clock, namely the single ion trap physics package and multi-wavelength dual-axis cubic cavity clock control unit have been redesigned to reduce SWaP. The optical cavity is needed to frequency stabilise the lasers for laser cooling and state preparation as well as the clock laser for interrogating the ion’s clock transition. We describe the results of finite element analysis (FEA) to model the electrical and thermal behaviour of a compact ion trap design. We also consider the design space for small cubic optical cavities, investigating the possible limits for achieving a minimal SWaP for the system.

DOI
10.21203/rs.3.rs-9855657/v1

Related papers

An ion trap design for a space-deployable strontium-ion optical clock

Alessio Spampinato, Jonathan Stacey, Sean Mulholland +5 more

Optical atomic clocks demonstrate a better stability and lower systematic uncertainty than the highest performance microwave atomic clocks. However, the best performing optical clocks have a large footprint in a laboratory environment and require specialist skills to maintain continuous operation. Growing and evolving needs across several sectors are increasing the demand for compact robust and portable devices at this capability level. In this paper we discuss the design of a physics package for a compact laser-cooled 88 Sr + optical clock that would, with further development, be suitable for space deployment. We review the design parameters to target a relative frequency uncertainty at the low parts in 10 18 with this system. We then explain the results of finite-element modelling to simulate the response of the ion trap and vacuum chamber to vibration, shock and thermal conditions expected during launch and space deployment. Additionally, an electrostatic model has been developed to investigate the relationship between the ion trap geometrical tolerances and the trapping efficiency. We present the results from these analyses that have led to the design of a more robust prototype ready for experimental testing.

arXiv:2401.12706•Proceedings of the Royal Society A Mathematical Physical and Engineering Sciences•Feb 1, 2024•7 citations

Subsystems and design for a transportable cold ion microwave clock

M. A. Trigatzis, Ulas Sabahattin Gokay, Martin Knapp +6 more

High performance transportable microwave atomic clocks are enablers for resilient GNSS-free timescales. We present progress towards a transportable laser-cooled ytterbium ion microwave clock. This system incorporates our recently developed multi-ion trap chamber and redesigned electronics and optics systems, offering reductions in size, weight and power, with improved performance over our previous system. The benchtop prototype version of this clock uses the new physics package design and reaches a short-term instability of 1.2 × 10−12/√τ. We present the transportable clock design as well as subsystem test results, which so far indicate that a similar performance to the benchtop version is achievable in a 3U rack-mounted package.

IET conference proceedings.•Aug 1, 2025•0 citations

Physics package validation and system integration for a low-SWaP, portable cold multi-ytterbium ion 12.6 GHz microwave clock

M. A. Trigatzis, Ulas Sabahattin Gokay, Martin Knapp +6 more

Abstract Compact atomic clocks provide the stable, traceable timing required for 5G/6G telecom networks, for resilient operation of critical infrastructure including power grids, data centres and financial systems, and for maintaining accurate synchronisation during GNSS interruptions or outages. Microwave clocks based on caesium beam tubes have been the industry-standard rack-mounted clock for many years but are now outperformed in short-to-midterm instability by emerging technologies. Vapour cell clocks suffer from long-term drift which must be calibrated out periodically and on startup. This limits their use for long-term holdover and in applications where the device needs to operate after a cold start. Additionally, optical clocks require a narrow-linewidth clock laser and optical frequency comb. The ytterbium ion microwave clock developed at the National Physical Laboratory (NPL) does not require these subsystems and combines this relative simplicity with the benefits of laser cooling (long-term stability, accuracy). In this paper, we describe an ion trap physics package design where its functionality has been evaluated in a benchtop clock and forms the basis of a new design for a compact, transportable clock. We describe the operation and performance of the benchtop clock, demonstrating a short-term fractional frequency instability of 1.4 × 10 − 12 /√τ. The design for a new transportable clock based on this new physics package is detailed, as are the validation tests of other key subsystems.

•Jun 18, 2026•0 citations

Single-ion, transportable optical atomic clocks

Marion Delehaye, Clément Lacroûte

For the past 15 years, tremendous progress within the fields of laser stabilization, optical frequency combs and atom cooling and trapping have allowed the realization of optical atomic clocks with unrivaled performances. These instruments can perform frequency comparisons with fractional uncertainties well below 10-17, finding applications in fundamental physics tests, relativistic geodesy and time and frequency metrology. Even though most optical clocks are currently laboratory setups, several proposals for using these clocks for field measurements or within an optical clock network have been published, and most of time and frequency metrology institutes have started to develop transportable optical clocks. For the purpose of this special issue, we chose to focus on trapped-ion optical clocks. Even though their short-term fractional frequency stability is impaired by a lower signal-to-noise ratio, they offer a high potential for compactness: trapped ions demand low optical powers and simple loading schemes, and can be trapped in small vacuum chambers. We review recent advances on the clock key components, including ion trap and ultra-stable optical cavity, as well as existing projects and experiments which draw the picture of what future transportable, single-ion optical clocks may resemble.

arXiv:1804.02168•Journal of Modern Optics•Mar 7, 2018•42 citations

Progress in the miniature trapped ion optical clock development with 16 cc sealed trap tube

Thai M. Hoang, Wei Zhang, Thanh Le +6 more

Abstract Optical clocks have well surpassed the frequency stability performance of microwave clocks. They have been mainly limited to tabletop setups and large rack-mount systems. Miniaturizing optical clocks will make the new technology and capability more ubiquitously applied to applications from navigation to fundamental science. Here we aim to develop a miniature space optical clock (mSOC) with the size of a compact microwave clock and capable of achieving a short-term stability of 10−14 τ −1/2 and noise floor of 10−16. In this paper, we will describe the mSOC concept, discuss the experimental setup, and present recent results. We have demonstrated trapping single ions and characterized the ion lifetime in a 16-cc trap tube. The trap tube is completely sealed off without any active pump. We also constructed a clock laser referenced to a small ultra-low expansion reference cavity at a low 10−14 level and observed the clock transition.

Journal of Physics Conference Series•Nov 1, 2024•0 citations

Prospects for quantum metrology with trapped-ion optical clocks in space

David R. Leibrandt

Terrestrial optical atomic clocks based on laser cooled atoms confined in the Lamb-Dicke regime in optical lattice traps or ion traps are the most precise and accurate measurement devices of any kind, and can be used to look for very small deviations from the predictions of the Standard Model that would hint at new physics. In this talk, I will discuss the design trade space for robust, autonomous, low-SWaP optical clocks for space, focusing primarily on trapped-ion clocks due to their lower complexity and laser power requirements. I will discuss the potential of integrated photonics to drastically reduce SWaP and increase robustness, and highlight performance targets for future development. Furthermore, I will discuss quantum metrology algorithms that can be used to alleviate the laser system performance requirements and suppress sensitivity to environmental noise. Finally, I will conclude by discussing the new physics reach of various optical atomic clock space flight mission scenarios.

Quantum Computing, Communication, and Simulation•Mar 5, 2026•0 citations
Abstract The primary technology for high accuracy position, navigation and timing (PNT) capability worldwide is currently provided by global navigation satellite systems (GNSS). The vulnerability of GNSS to intentional interference, clock component failure or extreme space weather is increasingly pointing to the need for alternative independent navigation and timing solutions to maintain critical national infrastructures, defence, security, commerce and logistics. The availability of low size, weight and power (SWaP) portable atomic clock technology with resilience and extended holdover times for use both in space and terrestrially is now increasingly urgent. In this paper, we report on progress in the development of compact optical clocks that offer the capability to out-perform existing commercial microwave atomic clock systems. We discuss designs for a compact transportable cold trapped strontium ion optical clock with both a low SWaP design and high accuracy that can address extended holdover for future navigation and timing requirements. We describe how key sub-systems of an optical atomic clock, namely the single ion trap physics package and multi-wavelength dual-axis cubic cavity clock control unit have been redesigned to reduce SWaP. The optical cavity is needed to frequency stabilise the lasers for laser cooling and state preparation as well as the clock laser for interrogating the ion’s clock transition. We describe the results of finite element analysis (FEA) to model the electrical and thermal behaviour of a compact ion trap design. We also consider the design space for small cubic optical cavities, investigating the possible limits for achieving a minimal SWaP for the system.
Optical atomic clocks demonstrate a better stability and lower systematic uncertainty than the highest performance microwave atomic clocks. However, the best performing optical clocks have a large footprint in a laboratory environment and require specialist skills to maintain continuous operation. Growing and evolving needs across several sectors are increasing the demand for compact robust and portable devices at this capability level. In this paper we discuss the design of a physics package for a compact laser-cooled 88 Sr + optical clock that would, with further development, be suitable for space deployment. We review the design parameters to target a relative frequency uncertainty at the low parts in 10 18 with this system. We then explain the results of finite-element modelling to simulate the response of the ion trap and vacuum chamber to vibration, shock and thermal conditions expected during launch and space deployment. Additionally, an electrostatic model has been developed to investigate the relationship between the ion trap geometrical tolerances and the trapping efficiency. We present the results from these analyses that have led to the design of a more robust prototype ready for experimental testing.
High performance transportable microwave atomic clocks are enablers for resilient GNSS-free timescales. We present progress towards a transportable laser-cooled ytterbium ion microwave clock. This system incorporates our recently developed multi-ion trap chamber and redesigned electronics and optics systems, offering reductions in size, weight and power, with improved performance over our previous system. The benchtop prototype version of this clock uses the new physics package design and reaches a short-term instability of 1.2 × 10−12/√τ. We present the transportable clock design as well as subsystem test results, which so far indicate that a similar performance to the benchtop version is achievable in a 3U rack-mounted package.
Abstract Compact atomic clocks provide the stable, traceable timing required for 5G/6G telecom networks, for resilient operation of critical infrastructure including power grids, data centres and financial systems, and for maintaining accurate synchronisation during GNSS interruptions or outages. Microwave clocks based on caesium beam tubes have been the industry-standard rack-mounted clock for many years but are now outperformed in short-to-midterm instability by emerging technologies. Vapour cell clocks suffer from long-term drift which must be calibrated out periodically and on startup. This limits their use for long-term holdover and in applications where the device needs to operate after a cold start. Additionally, optical clocks require a narrow-linewidth clock laser and optical frequency comb. The ytterbium ion microwave clock developed at the National Physical Laboratory (NPL) does not require these subsystems and combines this relative simplicity with the benefits of laser cooling (long-term stability, accuracy). In this paper, we describe an ion trap physics package design where its functionality has been evaluated in a benchtop clock and forms the basis of a new design for a compact, transportable clock. We describe the operation and performance of the benchtop clock, demonstrating a short-term fractional frequency instability of 1.4 × 10 − 12 /√τ. The design for a new transportable clock based on this new physics package is detailed, as are the validation tests of other key subsystems.
For the past 15 years, tremendous progress within the fields of laser stabilization, optical frequency combs and atom cooling and trapping have allowed the realization of optical atomic clocks with unrivaled performances. These instruments can perform frequency comparisons with fractional uncertainties well below 10-17, finding applications in fundamental physics tests, relativistic geodesy and time and frequency metrology. Even though most optical clocks are currently laboratory setups, several proposals for using these clocks for field measurements or within an optical clock network have been published, and most of time and frequency metrology institutes have started to develop transportable optical clocks. For the purpose of this special issue, we chose to focus on trapped-ion optical clocks. Even though their short-term fractional frequency stability is impaired by a lower signal-to-noise ratio, they offer a high potential for compactness: trapped ions demand low optical powers and simple loading schemes, and can be trapped in small vacuum chambers. We review recent advances on the clock key components, including ion trap and ultra-stable optical cavity, as well as existing projects and experiments which draw the picture of what future transportable, single-ion optical clocks may resemble.
Abstract Optical clocks have well surpassed the frequency stability performance of microwave clocks. They have been mainly limited to tabletop setups and large rack-mount systems. Miniaturizing optical clocks will make the new technology and capability more ubiquitously applied to applications from navigation to fundamental science. Here we aim to develop a miniature space optical clock (mSOC) with the size of a compact microwave clock and capable of achieving a short-term stability of 10−14 τ −1/2 and noise floor of 10−16. In this paper, we will describe the mSOC concept, discuss the experimental setup, and present recent results. We have demonstrated trapping single ions and characterized the ion lifetime in a 16-cc trap tube. The trap tube is completely sealed off without any active pump. We also constructed a clock laser referenced to a small ultra-low expansion reference cavity at a low 10−14 level and observed the clock transition.
Terrestrial optical atomic clocks based on laser cooled atoms confined in the Lamb-Dicke regime in optical lattice traps or ion traps are the most precise and accurate measurement devices of any kind, and can be used to look for very small deviations from the predictions of the Standard Model that would hint at new physics. In this talk, I will discuss the design trade space for robust, autonomous, low-SWaP optical clocks for space, focusing primarily on trapped-ion clocks due to their lower complexity and laser power requirements. I will discuss the potential of integrated photonics to drastically reduce SWaP and increase robustness, and highlight performance targets for future development. Furthermore, I will discuss quantum metrology algorithms that can be used to alleviate the laser system performance requirements and suppress sensitivity to environmental noise. Finally, I will conclude by discussing the new physics reach of various optical atomic clock space flight mission scenarios.