We give an up-to-date description of some present development issues, together with an architecture study and a systems engineering analysis, in the area of laser sources for the injection of the Laser Mega-Joule (LMJ), which are a part of the French ICF fusion program. After a brief description of the main concepts, the overview consists of two parts. The first one includes the standard first source (all-fiber design) that will be used for the activation of the facility of Ligne d'Integration Laser (LIL), the reduced-scale demonstrator under construction for the validation of the concepts and technology to be selected for the LMJ. The second one describes the state of the art in the prototyping of a new source, with extended performance with respect to optical noise and robustness, to be tested on LIL in a second step of the activation.