Quantum Atom-Fibre Photonics
Kagome fibre developed at the University of Bath
The advent of hollow-core photonic crystal fibre (pictured right) has revolutionised methods for creating strong interactions between light and matter. This is achieved by confining light and gas within the same small volume.
We make use of this technology to guide cold atoms through fibre, implement both classical and quantum optical switches and produce compact optical frequency standards.
Cold Matter Wave
We are combining cold-matter and photonic crystal fibres to develop a platform technology for quantum information applications and matter-wave optics. We are currently transferring cold-atoms from a magneto-optical trap into an optical fibre using optical guide beams to both perform the transfer, and prevent the cold atoms from colliding with the core-wall of the fibre (and thus heating).
We are also investigating the potential for using this optical-fibre based technology for creating a matter-wave beamsplitter for inertial sensing applications.
Optical technology has shown to be a promising platform for quantum communication and computing. To produce a universal quantum computer efficient photon-photon interactions are required to perform certain logic operations. However, currently there are no efficient methods to this interaction. Furthermore, optical communications and computing is fast approaching bandwidth issues and speed limitations with existing technology.
To circumnavigate this problem the push is on to find optical solutions such as replacing electronic switches with optical switches in telecommunications. To address these issues we use the properties of hollow-core fibre to generate a non-linear interaction between two laser beams mediated by a Rubidium vapour. This non-linear interaction is capable of switching off one laser beam when the second laser is turned on, hence producing an optical switch. We are pushing the boundaries of this technology to maintain this strong interaction down to the single photon level.
Compact Rubidium/Iodine Frequency Standards
Currently atomic frequency standards find uses in the Global Positioning System (GPS), telecommunications, National facilities which disseminate time, and currently define the temporal second. Unfortunately the most accurate and precises frequency standards occupy entire laboratories and cannot be easily deployed into the field for real world applications. Here we are using the technology of hollow core photonic crystal fibre to both: shrink the size of the frequency standard, and produce efficient excitation of desirable atomic transitions.
For the Rubidium frequency standard we use a two-photon transition which is excited in a Doppler free configuration to reveal the narrow linewidths of the excited state. This technique allows us to produce a frequency standard with a fractional stability in the 10-12 range. Within the Iodine frequency standard we perform saturated absorption spectroscopy to produce narrow linewidth features that are the basis of the frequency standard. This technique allows us to produce a frequency standard with a fractional stability in the 10-12 range.
Quantum Stet Storage and Manipulations
High-Bandwidth Quantum Memory in Hollow-Core Fibre
The ability to store and manipulate optical quantum information is crucial for delivering next-generation computing, protect privacy with absolutely-secure communications and provide ultra-precise measurement standards.
The extreme atom-light interaction strengths within our Rubidium-filled hollow-core fibres provide the ideal environment for efficient storage and retrieval of photons. We are combining these with state-of-the-art quantum storage techniques to delivering a compact, robust and modular “quantum node”. This node will integrate directly with current communications infrastructure, allowing for the creation of a quantum internet – the vital missing ingredient needed to overcome the experimental hurdles that are limiting the potential of current quantum technologies.