Ultimate Wave-Packet ControlDuring the past few decades, two techniques have transformed the ways in which researchers can probe molecular processes: coherent control over dynamic processes by manipulating quantum interference effects with shaped laser pulses, and single-molecule detection. Now ICFO PhD Student Daan Brinks and colleagues, led by ICFO/ICREA Prof. Niek van Hulst, show that the two approaches can be combined, allowing not only the observation, but also the manipulation of vibrational wave-packet interference in individual molecules at ambient conditions. The single-molecule approach ensures that the ultimate degree of coherent control can be realized, which could help unravel details of molecular function and how it may be affected by dynamics in systems as diverse as conjugated polymers, light-harvesting complexes and photo-active proteins.

When light propagates in a disordered material, information is seemingly lost. This is why we can't see through most biological samples. Nonetheless, propagation of waves in complex media give rise to a lot of interesting physics, ranging from photonic crystals to Anderson localization, from strong coupling to quantum correlations.

Recently, a method has been proposed by A. Mosk and coworkers to focus light through a multiple scattering material, using a spatial light modulator as a tool to shape the incoming beam to obtain a maximal interference on a speckle spot of the output speckle pattern. The result is a diffraction limited spot which can be several hundred time brighter than the rest of the speckle.