Influence of Photon Mass on Vacuum Birefringence Experiment

Influence of photon mass on vacuum birefringence experiment is analysed according to the nonlinearities of vacuum quantum electrodynamics for the light propagation through an intense electromagnetic field. It is shown that although the photon mass will cause a change of the refractive indices n_⊥ and n_|| of vacuum birefringence, the difference n_||-n_⊥ is unchanged, which means that the effect of photon mass cannot be observed in vacuum birefringence experiment.