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Laser radiation with less coherence


The use of lasers as a light source for imaging systems has great advantages – e.g. due to the exactly known wavelength – but also one disadvantage: owing to the spatial coherence of the laser beams, so-called “speckle artefacts” occur. Conventional procedures for the reduction of the coherence are not suited for pulsed laser radiation with a low repetition rate and a great coherence length. Thanks to an invention of PTB, speckle suppression is possible. It mainly consists of a new fibre coupling method and can be used in different optical microscopes in which lasers or super LEDs are used as light sources. The technology can be realised with extremely little technical and economic effort, and is also suited for non-imaging systems.