Abstract This chapter introduces general frame-independent relations between the observable anisotropy parameters. Some of these reflect geometrical properties distribution, including inequalities that delimit allowed phase space parameters, and representation distribution in a “canonical” form. The most interesting relation defines rotation-invariant parameter expressing intrinsic nature polar...

Based on the method of the vectorial angular spectrum, an analytical expression of the electric field of an elegant LaguerreGaussian beam in free space is derived beyond the paraxial approximation, and the corresponding magnetic field is obtained by taking the curl of the electric field. By using the expressions for the electromagnetic fields, the expression of the orbital angular momentum dens...