CHANGES IN THE PROFILE AND STATE OF POLAR IZATION OF A SHORT LIGHT-PULSE (LAMBDA-SIMILAR-TO-1.06-MU-M) DURING PROPAGATION IN A YAG-CR4+ CRYSTAL

An investigation was made of changes in the profile and state of polar isation of a short (25 ns) resonant light pulse (lambda approximately 1.06 mum) during its propagation in a YAG:Cr4+ crystal. The experiment al results were in good agreement with a theory in which the absorptio n of light by the Cr4+ impurity centres in a YAG crystal is described phenomenologically as a consequence of the interaction of light with t hree orthogonal groups of resonant linear dipoles. The results demonst rated the feasibility of control of the profile of a light pulse propa gating through a polariser-YAG:Cr4+ crystal-polariser system. The appl ication of a single frequency pulse to this system generated output pu lses with or three intensity maxima. This was a direct result of a sel f-induced change in the polarisation of light in a YAG:Cr4+ crystal at the saturation absorption stage.