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The Earth would be barren and uninhabitable without the light of the sun, for without its precious rays of bright light there would be no photosynthesis, no oxygen and thus no life on our planet. For human civilisation, producing and controlling artificial light is just as important as sunlight.
Light has extraordinary properties
In terms of its physics, light is extraordinary: although it is made up of elementary particles known as photons or light quanta, light oscillates in waves – which move at a constant rate of 300,000 kilometres per second. Light does not require any transmission medium. If we understand the structure and oscillation of light, if we are able to produce it and control its properties, we can turn light into a tool with an infinite variety of amazing functions.
Important in many areas of everyday life
“Light can be used for the contactless transmission of information and energy across distances”, says Professor Gerd Leuchs, one of the directors of the Max Planck Institute for the Science of Light, which was founded in Erlangen in 2009. “As a result, technologies revolving around light have been developed, with many applications now in everyday use. For example, the transmission of large quantities of data across huge distances through fibre optic cables, the virtually instantaneous identification of objects using laser scanners at the supermarket checkout or the use of lasers to cut material in industry.”
Source of new research fields
The physical phenomenon that is light has spawned a number of dynamic and growing fields of research. “Over the past two decades there have been unimaginable breakthroughs in microscopy that are nothing short of revolutionary”, reports Leuchs. Laser light is allowing researchers to penetrate matter more and more deeply. Nobel laureate Professor Stefan Hell in Göttingen for example has developed a microscope that can be used to view objects lying very close to one another or indeed on top of one another, such as molecules in a cell – with a degree of resolution previously unattainable by optical microscopes. Together with his team at Munich’s LMUand TUM universities, Professor Ferenc Krausz is exploring how ultrashort pulse lasers can be used in cancer diagnosis. The researchers want to make cancer cells visible at a very early stage, as tumours can be treated more easily when they are still very small.
“Then there is the role played by light in quantum information processing nowadays”, says Gerd Leuchs. His own research group at the Max Planck Institute in Erlangen is studying the quantum phenomena that can be used to transmit large quantities of information at a much faster speed than is currently possible. Working with researchers at Friedrich-Alexander-Universität Erlangen-Nürnberg, the physicists are trialling a new method: they use powerful flashes of light to transport quantum information through the air – in a way that is entirely tap-proof. This already works in a test facility in Erlangen, and is soon to be put to the test across longer distances. Researchers will then be sending packages of light loaded with information to a satellite in space – at the speed of light, naturally.