For the International Thermonuclear Experimental Reactor (ITER), the core electron temperature and density should be measure by a diagnostic. It is proposed to measure this with a LIDAR Thomson scattering system, with a laser beam injected approximately horizontally through an equatorial port. The scattered light from the laser beam directed towards the core plasma will be collected trough an optical labyrinth. This project is to participate to the design of this diagnostic and mostly work on the optical components.