  We investigate on-chip spectral control of supercontinuum generation, taking
advantage of the additional spatial degree of freedom in strongly-coupled
dual-core waveguides. Using numerical integration of the multi-mode generalized
nonlinear Schr\"odinger equation, we show that, with proper waveguide
cross-section design, selective excitation of supermodes can vary the
dispersion to its extremes, i.e., all-normal or anomalous dispersion can be
selected via phase shifting in a Mach-Zehnder input circuit. The resulting
control allows to provide vastly different supercontinuum spectra with the same
waveguide circuit.
