The objective of the ICLM project "Coherent Imaging of Multi-scattered Light" is to study light propagation through scattering media with different original techniques based on coherent interferometry, in order to apply it to biological media. This requires to work within the 650-1100nm spectral range in order to minimize absorption effects. One can extract information from the complex output field by interferometry with an external reference beam (two-wave mixing), and get a millimetric spatial localization by coupling light with an ultrasonic wave within the scattering medium (acousto-optic effect). One can generate by three-wave mixing a phase-conjugate beam, that once back-propagated within the medium, restores the input beam (plane wave) with the cumulated information of local absorption properties (phase conjugation process). But an efficient collection of these multi-scattered photons is puzzling in terms of flux, because the optical etendue of the output field (speckle) is huge, especially for thick media. Moreover, as it is the case for living tissues, this speckle field is not stationary versus time because of inner motions, and thus a coherent detection must be performed during a relatively short acquisition time (millisecond). The ambition of this project is multiple, since we wish to : 1 - Perform an efficient acousto-optic imagery and apply it to biological tissues, with a millimetric resolution. 2 - Understand and modelize back-propagation within the medium following the phase conjugation process. 3 - Control the spatial structure of the wavefront in order to optimize the propagation within the medium. We will use in two-wave mixing configuration a digital heterodyne off-axis holography in order to select photons that have crossed the ultrasonic field, and also a wavefront adaptive holography using original photosenstive materials at 800 and 1064nm (photorefractive crystals, gain media), which is well suited for biological media. We will also evaluate a new promising type of detection based on the spectral holeburning phenomenon. Phase-conjugation process will be generated in real time (picosecond source) by parametric amplification, making a three-wave mixing within a non-linear crystal, or considering the photosensitive materials used in the two-wave mixing configuration. The active control of the wavefront transmitted by the medium will be considered with spatial light modulators in order to study the properties of phase conjugation, and test the existence of Pendry's "Open Channels" within the medium.