Researchers from the University of Glasgow have created a digital image of a wasp’s wing using fewer than one photon per pixel.
The work is based on quantum imaging where photons are paired so that any measurement of one instantaneously gives knowledge of the state of the other. Fifty thousand photons were used to create the image, none of which ever directly interacted with the wing itself.
The experiment is calibrated so that information is only collected when a photon strikes a detector after passing through the wasp wing. This detector is also the source for the actual count of 50,000 photons.
Professor Miles Padgett, head of the Optics Group in the University of Glasgow’s School of Physics and Astronomy, said: ‘Imaging in extremely low light like this can be useful in areas where more intense light can damage or fade very fragile materials. It also has applications in biological imaging and defence.’
The work was published in Nature Communications. The project is the latest in a series of quantum imaging research at the University of Glasgow, which was recently announced by the UK Government as the lead in a £29m Quantum Imaging Hub.
The UK’s Technology Strategy Board, Innovate UK, will invest £32 million over five years in quantum technologies, according to Anke Lohmann, head of photonics at the UK’s Knowledge Transfer Network.
Reuben Aspden, who helped build the system, said: ‘Our system works by sending ultraviolet light from a laser to a non-linear crystal similar to a piece of quartz. The crystal splits every incident ultraviolet photon into two infrared photons, which exit the crystal on separate trajectories in a state of quantum entanglement.’
Peter Morris, a graduate student working on the project, added: ‘One photon illuminates the wasp wing while the other photon goes to the camera sensor. Because the photons are entangled and share information between them on a quantum level, the image is formed on the camera’s sensor by photons which have never actually “seen” the object for themselves.’
The research was supported by funding from the Engineering and Physical Research Sciences Council (EPSRC) and the European Research Council (ERC).
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Further information:
Optics Group, University of Glasgow
Imaging with a small number of photons, Nature Communications
