Measuring the transmission matrix in optics: an approach to the study and control of light propagation in disordered

We introduce a method to experimentally measure the monochromatic transmission matrix of a complex medium in optics. This method is based on a spatial phase modulator together with a full-field interferometric measurement on a camera. We determine the transmission matrix of a thick random scattering sample. We show that this matrix exhibits statistical properties in good agreement with random matrix theory and allows light focusing and imaging through the random medium. This method might give important insights into the mesoscopic properties of complex medium. PACS numbers: The propagation of waves in heterogeneous media, espe-cially in the multiple scattering regime, is a very fundamental problem of physics with numerous applications ranging from solid-state physics and optics, to acoustics and electromag-netism [1]. The behavior or such media is usually described by their average macroscopic properties such as the scattering and absorption mean free paths, and via spectral or temporal properties, such as spectral resonances or confinement times