Our research mainly concerns electromagnetic phenomena, where we initiated the field of metamaterials, a new concept giving rise to extraordinary new material properties. In addition transformation optics is a mathematical tool for creating novel devices which has been applied to the problem of invisibility and to focussing of light beyond the wavelength limit. Optics and quantum phenomena are closely connected and our work provides unique control of electron photon coupling through plasmonic systems. Sensors can exploit the extreme coupling, and applications to novel lasing devices are being explored. Our work on quantum information theory led us to predict quantisation of thermal conductivity in terms of the fundamental constants, now verified experimentally in two different experimental systems.
We (the Quantum Nanophotonics team in the Centre for Cold Matter) are working to build photonic quantum technology using cold organic molecules coupled to integrated waveguides and cavities. These include an on demand photon source, photonic information processors, and photon storage and memories.
We develop novel laser sources for a range of applied applications, from exacting engineered lasers developed towards satellite-based remote sensing for the European Space Agency (ESA) to ultra-high precision wavelength tunable lasers with lower-cost and size than existing systems being developed to enable future commercial Quantum Technology applications.
The group’s primary objective is the development and application of versatile, fibre-baser laser technology. Non-linear optical techniques are deployed to extend the capabilities of fibre integrated systems in master-oscillator power fibre amplifer configurations that exhibit high efficiency, a small footprint, high stability and effectively hands-free operation, permitting extensive flexibility in wavelength, linewidth, pulse duration (from femtosecond to CW) and pulse repetition rate, substantially beyond that achievable with conventional solid state laser technology. Wavelength operational regimes extend from the UV to the mid-IR and applications range from imaging to remote sensing.
Quantum coherence on macroscopic scales is established when a system of identical bosons at thermal equilibrium occupy the ground state in enormous numbers. This effect can be found in many physical systems, such as cold atoms below about 100 nK, in helium at 2K, and recently in photons at room temperature. To make photons condense we need to give them a non-zero minimum energy. In a 1.5-micron long, dye-filled optical resonator, we can achieve both thermal equilibrium of the light and a well-defined ground state. We optically pump the dye, and increasing the pump power increases the number of photons. When there are enough photons, they undergo Bose-Einstein condensation (BEC), which shows up in the spectrum and the image of the light which leaks out of the resonator. We are testing how this thermodynamic description stands up when there only a handful of photons present at the condensation threshold, and what quantum correlations among the photons are present.