Manipulating and Measuring Modes in Multimode Fibres

Advances in the measurement and manipulation of light’s spatiotemporal properties are overcoming many of the practical difficulties which have traditionally limited the applications of multimode optical fiber. Applications such as mode division multiplexing (MDM) exploit fiber modes to increase transmission capacity for telecommunications, while biomedical imaging is employing multimode fibre to create endoscopes at the theoretical limits of compactness. These new techniques require multimode fibre propagation to be characterized and controlled with a level of detail not previously available and in doing so, it is also yielding insights into the fundamentals of fibre optics itself. For example by the observation of well-known, but previously unobserved phenomena such as principal modes.