A single optical fibre could form the basis of thinner endoscopes — long imaging probes with medical, military and industrial uses.

Current endoscopes are made up of millimetre-sized bundles of up to 100,000 fibres. Each fibre transports a single mode of light wave coming from the object being imaged, because the mixing of modes can cause light-wave distortion.

Wonshik Choi at Korea University in Seoul and his colleagues have used a single 200-micrometre-wide fibre to transport multiple modes, by measuring and reverse engineering the distortion that each mode suffers. The authors used their technique to make a three-dimensional map of a sample of rat intestine.

Phys. Rev. Lett. 109, 203901 (2012)