The invention concerns a method for optical recording of data on a photosensitive
storage medium, characterized in that the data are encoded according to different
possible states for the various components of a non-linear susceptibility tensor
of the photosensitive medium and it consists in irradiating simultaneously at least
a point of said support with write beams whereof the polarization is controlled
for optical recording of a given non-linear susceptibility tensor on the photosensitive medium.