Light by light diffraction in vacuum

Understand

We show that a laser beam can be diffracted by a more concentrated light pulse due to quantum vacuum effects.

• We compute analytically the intensity pattern in a realistic experimental configuration, and discuss how it can be used to measure for the first time the parameters describing photon-photon scattering in vacuum.
• In particular, we show that the Quantum Electrodynamics prediction can be detected in a single-shot experiment at future 100 petawatt lasers such as ELI or HIPER.
• On the other hand, if carried out at one of the present high power facilities, such as OMEGA EP, this proposal can lead either to the discovery of non-standard physics, or to substantially improve the current PVLAS limits on the photon-photon cross section at optical wavelengths.