Ultrafast adiabatic control of reciprocity and coherent backscattering in random scattering media

We experimentally demonstrate ultrafast control over reciprocal light paths in random media. The combination of multiple scattering and coherence of light gives rise to strong interference contributions in light transport. An important interference correction to diffusion theory is the coherent backscattering effect, the constructive interference of reciprocal light paths in the backscattering direction. Our experiments show that the phase coherence between these paths can be suppressed by introducing dynamics faster than the photon dwell time. This adiabatic dephasing is of interest for its potential for controlling weak and strong localization and adiabatic storage and release of photonic information