Towards a complete $γγ\to 4~$leptons Monte Carlo

The total cross-section of the $\gamma \gamma \to 4 $ leptons process is known to have a large constant value at high energy, but a complete and exact calculation of related differential spectra does not exist yet. However a complete study of the process is important at NLC for luminosity measurements or for background estimations. We here report on our various steps in that direction, including the implementation of a first new calculation of helicity amplitudes in a Monte-Carlo generator.