  In this paper we propose an all-optical vacuum birefringence experiment and
evaluate its feasibility for various scenarios. Many petawatt-class lasers
became operational and many more are expected to enter operation in the near
future, therefore unprecedented electromagnetic fields
($E_L\sim10^{14}-10^{15}$ V/m and intensities $I_L\sim10^{21}-10^{23}$
W/cm$^2$) will become available for experiments. In our proposal a
petawatt-class laser disturbs the quantum vacuum and creates a delay in a
counter-propagating probe laser beam. Placing this delayed beam in one arm of a
Mach-Zehnder interferometer (MZI), allows the measurement of the vacuum
refraction coefficient via a phase shift. Coherent as well as squeezed light
are both considered and the minimum phase sensitivity evaluated. We show that
using existing technology and with some moderately optimistic assumptions, at
least part of the discussed scenarios are feasible for a vacuum birefringence
detection experiment.
