Detailed measurement of the phase distribution of an optical beam with inverting vortex.

The detailed phase distribution of an astigmatic optical beam with inverting vortex is measured with a polarization based phase shifting interferometry. Energy flows and angular momentum density distribution within the beam cross sections are calculated from experimental data. Positive and negative angular momentum regions are observed both before and after vortex inversion, and regions of pure radial flow are identified. [ABSTRACT FROM AUTHOR]