Harnessing chaos for enhanced coupling: Functional optical devices typically require the coupling of light between different components. However, conservation of momentum usually limits the bandwidth of the coupling, often to a near-resonant effect. Jiang et al. show that slightly deformed microring resonators might be able to relax those restrictions. The chaotic scattering of the light within the deformed structure can transform optical modes of different angular momenta within a few picoseconds, providing a promising route to develop advanced nanophotonic circuits and devices. Science , this issue p. 344