Detection of vacuum birefringence using intense laser pulses

We propose a novel technique that promises hope of being the first to directly detect a polarization of the quantum electrodynamic (QED) vacuum. The technique exploits the high fields associated with ultra-short pulses of light stored in low dispersion optical resonators. We show that the technique circumvents the need for large-scale liquid helium cooled magnets, and more importantly avoids the experimental pitfalls that plague existing experimental approaches that use these magnets. The new technique has a predicted birefringence measurement sensitivity of Δn10⁻²⁰ in a 1 s measurement. Currently available optics and lasers will enable observation of vacuum polarization in an experiment of only a few days in duration.