PHOTON-PHOTON ELASTIC-SCATTERING IN THE VISIBLE DOMAIN

We are investigating the direct detection of photon-photon elastic sca ttering at optical energies. In a first experiment using two high-inte nsity pulsed laser beams, we have explored the feasibility of the meth od, and in particular the rejection of back-ground noise. We obtained an upper limit of the photon-photon elastic scattering cross section a t 95% confidence level of 10(-39) cm(2). This limit can be lowered by twenty orders of magnitude by stimulating the scattering by a third be am, and by using high repetition rate existing lasers.