Abstract: Embodiments relate to generating a configuration of waveguide propagation constants formed in a waveguide array system. The configuration of propagation constants can be made via a recursive detuning process that produces approximations to a fractal structure designed to maximally localize eigenstates of a waveguide array. The eigenstates being maximally localized enables strong suppression of crosstalk between the waveguides. Performing more detuning iterations can produce a configuration of propagation constants that better approximates the fractal structure and suppresses crosstalk over larger distances.