Phase corrections for synchrotron radiation

High accuracy calculations of synchrotron radiation (SR) emitted by a relativistic electron show that the phase of the frequency domain electric field of SR differs from the phase of radiation of a virtual point source. These differences may result in the reduction of focusing efficiency of diffraction-limited SR, if the focusing is performed by conventional optical components optimised for point sources. We show that, by applying a phase correction locally, one may transform the phase of SR electric field at a desired polarisation to that of a point source. Such corrections are computed for undulator and bending magnet radiation.