Activity: Talks and presentations › Guest lectures, external teaching and course activities at other universities
Stephan Smolka - Speaker
When light propagates through a disordered nanophotonic medium it is multiple scattered and classical information, e.g., the direction of propagation tends to be lost. Surprisingly, this turns out to be different for quantum light. We demonstrate experimentally spatial quantum correlations that are induced by multiple scattering of non-classical light. The correlations are of purely quantum origin and we show that the number of photons scattered into one direction can be predicted from the number of photons detected in a different direction. A further intriguing phenomenon arises when light interferes strongly in disordered nanophotonic media. Philip Anderson was awarded with the Nobel price for his proposal that disorder can localize light. We show that Anderson localization is indeed very suitable to enhance the interaction between light and matter which is the essence of many research disciplines such as quantum information science and energy harvesting. The traditional way has been to strongly confine light in, e.g., a highly engineered nano-cavity. Inducing a certain amount of randomness in a photonic crystal waveguide, disorder-induced Anderson-localized modes can form spontaneously. We observed a dramatic 15fold enhancement in the spontaneous emission rate of a quantum dot single photon source coupling it to a localized mode. Employing fabrication disorder in photonic crystals as a resource rather than a nuisance therefore paves an entirely new approach to cavity quantum electrodynamics.
20 Apr 2010