Experimental evidence for supercontinuum generation by fission of higher-order solitons in photonic crystal fibers

Summary form only given. Photonic crystal fibers (PCF) are currently a topic of high interest because of their unusual optical properties and their large potential for important applications such as e.g. frequency metrology. As a result of the novel dispersion characteristics of PCFs such as a shift of the zero-dispersion wavelength into the visible region, new features in nonlinear optical effects arise that can not be observed in standard optical fibers. One such phenomenon is the generation of an extremely broadband supercontinuum (SC) covering more than two octaves from low-energy pulses. In comparison, SC generation in standard fibers requires more than two orders of magnitude higher initial peak intensities. Here we present the experimental evidence that low-intensity SC generation in PCFs is caused by a previously unknown mechanism for ultra-wide spectral broadening. The low-intensity spectral broadening observed in PCFs can not be explained by the effect of SPM for low-energy pulses Recent theoretical work has given a surprising explanation: SC generation in the anomalous dispersion region is caused by fission of higher-order solitons into fundamental solitons. In direct contrast to SPM, for which shorter pulses are more favorable, SC generation by fission of N-solitons is more effective for long pulses, which can be used as a test for soliton-induced SC generation.