Supersymmetry-guided method for mode selection and optimization in coupled systems.

Single-mode operation of coupled optical 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 10-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.