Quantum Rydberg sensors offer a fundamentally different approach to electric field (E-field) measurement and radio frequency (RF) sensing. Unlike conventional metal antennas and electronic receiver circuits, these sensors use the well-defined properties of atoms to directly measure electromagnetic fields.
Their atomic nature enables operation across an exceptionally wide frequency range, from low frequencies through to microwave and terahertz regimes, using a single sensing platform. This creates new opportunities for spectrum monitoring, precision metrology and non-invasive field measurements.
As the UK's National Measurement Institute, NPL is developing fibre-coupled Rydberg sensor technologies to strengthen the UK's electric field measurement capabilities and support emerging applications in communications, defence, aerospace and advanced sensing.
Supporting innovation across UK industry is a key part of NPL's mission. We welcome opportunities to collaborate with organisations developing quantum technologies, advanced communications systems and novel sensing applications.
Whether you are exploring Rydberg sensing for research, product development or measurement challenges, we would be interested in discussing how NPL's expertise and facilities can support your work.
Rydberg sensors are based on alkali-metal atoms contained within a vapour cell. Using a multi-photon laser excitation schemes, atoms are driven into highly excited Rydberg states.
In these states, the outer electron is extremely sensitive to external electric fields. When an electric field is present, it alters the atomic energy levels in a predictable and measurable way.
By exploiting a quantum-optical technique known as electromagnetically induced transparency (EIT), changes in the atomic states can be detected optically. RF and microwave signals are therefore converted into optical signatures, enabling direct measurement of the electric field interacting with the atoms.
Because the measurement is linked to fundamental atomic properties, Rydberg sensors provide an intrinsically quantum-based approach to E-field sensing.
Rydberg sensors measure electric fields through well-defined atomic transitions. The measurement is directly referenced to fundamental quantum properties, reducing reliance on conventional calibration approaches.
A single sensor platform can operate across an exceptionally broad frequency range, supporting applications that would traditionally require multiple antennas and receiver architectures.
The strong interaction between Rydberg atoms and electromagnetic fields enables the detection of weak signals while maintaining excellent spectral selectivity.
As atomic sensors do not rely on traditional metallic receiving elements, they offer new possibilities for measurements in challenging electromagnetic environments.
NPL is developing fibre-coupled architectures that enable flexible sensor deployment while maintaining access to high-quality optical interrogation systems.
NPL's current focus is on establishing the metrological foundations required for reliable and traceable quantum E-field measurements.
By combining expertise in quantum technologies, communications systems and measurement science, we are investigating how Rydberg sensors can be used to deliver highly accurate measurements of signal magnitude, phase and other key electromagnetic parameters.
This work supports the development of future standards, measurement methods and sensing capabilities for next-generation wireless and RF technologies.
Potential applications of Rydberg sensing include: