Adiabatic bend transitions for large mode area fibres

Adiabatic bend transitions in large mode area multimode fibres were investigated theoretically using the beam propagation method. Adiabatic bend transducers preserve the power of guided light in the fundamental mode while guiding from one level of curvature to another for improved operation of mode filters and fibre amplifiers. A method is shown and used to find the optimised guidance path. Applications of these transducers include modal power back-converters, and guidance paths into and out of higher order mode filtering devices which work on bending.