  Single-mode operation of coupled systems such as optical-fiber bundles,
lattices of photonic waveguides, or laser arrays requires an efficient method
to suppress unwanted super-modes. Here, we propose a systematic
supersymmetry-based approach to selectively eliminate modes of such systems by
decreasing their lifetime relative to the lifetime of the mode of interest. The
proposed method allows to explore the opto-geometric parameters of the coupled
system and to maximize the relative lifetime of a selected mode. We report a
ten-fold increase in the relative lifetime of the fundamental modes of large
one-dimensional coupled arrays in comparison to simple 'head-to-tail' coupling
geometries. The ability to select multiple supported modes in one- and
two-dimensional arrays is also demonstrated.
