We propose coupled-cavity triply-resonant systems for degenerate-pump four-wave mixing (FWM) applications that support strong nonlinear interaction between distributed pump, signal and idler modes, and allow independent coupling of the pump mode and signal/idler modes to separate ports based on nonuniform supermode profile. We demonstrate seeded FWM with wavelength conversion efficiency of -54 dB at input pump power of 3.5 dBm, and discuss applications of such orthogonal supermode coupling. (C) 2015 Optical Society of America