Dynamic active wave plate using random nanoparticles

Current non-invasive imaging and manipulation of biological systems heavily rely on using light as the probing tool. However, light propagation through highly turbid media such as biological tissue undergo multiple light scattering which results in significant scrambling of light paths and polarization information. Here we demonstrate the full control of polarization dependent light paths through a highly scattering medium by only shaping the incoming wavefront. The resulting polarized state is independent of the incident beam's polarization and has no spatial restrictions. We also show that a turbid medium can be used as a dynamic wave plate by controlling the phase of combined orthogonal polarization states. This approach may find direct applications in efficient energy transfer for photothermal therapy and the transfer of angular momentum in optical manipulation of biological systems. (C) 2012 Optical Society of America