Exploiting the Time-Reversal Operator for Adaptive Optics, Selective   Focusing and Scattering Pattern Analysis
  We report on the experimental measurement of the backscattering matrix of a weakly scattering medium in optics, composed of a few dispersed gold nanobeads. The DORT method (Decomposition of the Time Reversal Operator) is applied to this matrix and we demonstrate selective and efficient focusing on individual scatterers, even through an aberrating layer. Moreover, we show that this approach provides the decomposition of the scattering pattern of a single nanoparticle. These results open important perspectives for optical imaging, characterization and selective excitation of nanoparticles. 
S\'ebastien Michel Popoff, Alexandre Aubry, Geoffroy Lerosey, Mathias   Fink, Albert-Claude Boccara, Sylvain Gigan
physics.optics