This photograph was taken by illuminating a piece of “photonics bandage fibre” under a white-light microscope.
The fibre is formed by stacking rods of germanium – a shiny grey semi-metal – doped in silica in a hexagonal pattern.
The centre rod is replaced with just silica to form the fibre’s core.
The colourful patterns pictured arise from the silica guiding white light through the structure.
This microstructure acts as a filter for certain wavelengths.
University of Bath physicists say they have developed a technique to more reliably produce single photons that can be imprinted with quantum information, which will help in processes such as quantum computing, secure quantum communication and precision measurements at low light levels.
Photons – particles of light – can be imprinted with information that can be used for things like carrying out calculations and transmitting messages.
To do this, individual photons need to be created – a difficult process, says the university.
Researchers from its Centre for Photonics and Photonic Materials have implemented a new way to improve the performance of single-photon sources using fibre optics and fast optical switches.
They combined several individual sources of photons using optical switches, a technique called multiplexing, using fibre optics fabricated at the university.
The resulting device not only makes generating single photons more reliable but also allows the control of properties of the photons created, including their colour.