The propagation of light can be radically controlled with tailor-made nanostructures, called photonic crystals. The main feature of such crystals is a forbidden gap: waves with colors within a forbidden range travel only a limited distance - called Bragg length - before being reflected due to Bragg interference. Scientists have discovered a method to tunably steer light deep into photonic crystals, to depths well beyond the Bragg length. By spatially shaping the incident waves, the energy ...
