Power scaling of dispersive-wave generation in higher-order optical fiber modes

Dispersive-wave generation in higher-order HE 1 l modes of step-index optical fibers is studied numerically. The limits to power scaling from nonlinear intermodal couplings are investigated. It is shown that single-mode operation is possible up to power levels of a few MW, whereas both pump and dispersive-wave power distributes over several modes for higher powers, making the frequency conversion process less specific and efficient. The use of a circularly polarized pump is found to be beneficial for power scaling, both due to a reduced effective nonlinearity, and a reduction in intermodal couplings to LP 2 l -like modes.