The continuing development of new and powerful laser sources that are able to deliver intense light beams motivates a widespread effort to model and simulate the interaction between these light beams and matter.

In this paper, the authors simulate the interaction between intense laser radiation and a fully ionized plasma by solving a Vlaslov-Maxwell system with the particle-in-cell (PIC) method. They develop a single program multiple data (SPMD) 3D PIC code, CALDER, which is relativistic and based on a spatial decomposition.

The paper presents some optimizations to achieve large simulations, such as communication overlapping and cache-friendly data management. The use of a parallel sparse preconditioned conjugate gradient (PCG) solves the Poisson equation. The authors present the advantages of these optimizations on the IBM SP3.