Linear and Circular Dichroism in the Double Photoionization of Helium

Abstract

Energy- and angle-resolved triply differential cross sections have been measured in the double photoionization of helium under equal and unequal energy sharing conditions using right- and left-elliptically polarized photons. Linear dichroism in these cross sections has been observed under the equal energy sharing. For the unequal energy sharing a pure circular polarization effect has been deduced by eliminating the linear polarization contribution.