Using high-power lasers for detection of elastic photon-photon   scattering
  The properties of four-wave interaction via the nonlinear quantum vacuum is investigated. The effect of the quantum vacuum is to generate photons with new frequencies and wave vectors, due to elastic photon-photon scattering. An expression for the number of generated photons is derived and using state-of-the-art laser data it is found that the number of photons can reach detectable levels. In particular, the prospect of using the high repetition Astra Gemini system at the Rutherford Appleton Laboratory is discussed. The problem of noise sources is reviewed, and it is found that the noise level can be reduced well below the signal level. Thus, detection of elastic photon-photon scattering may for the first time be achieved. 
E. Lundstrom (UmU/SU, Sweden), G. Brodin (UmU, Sweden), J. Lundin   (UmU, Sweden), M. Marklund (UmU, Sweden), R. Bingham (RA...