INTENSITY-DEPENDENT SPECTRA OF PULSES PROPAGATING IN OPTICAL FIBERS

Using computer simulations, we examine the effects of higher-order dispersive and nonlinear propagation processes on the spectral development of ultrashort, high-intensity pulses propagating in normally-dispersive fibers. Both the cubic dispersion term and the 'shock' term of the nonlinear Schroedinger equation each contribute to asymmetry in the pulse power spectrum. This asymmetry depends on the particular combination of these higher-order effects. Our results indicate that the two effects, cubic dispersion and the shock term, can contribute significantly toward explaining recent compression experiments when both are incorporated into the nonlinear Schroedinger equation.