The effect of orbital angular momentum and helicity in the uncertainty-type relations between focal spot size and angular spread

It is well known that, for any monochromatic field, the spatial extent of the focus has a lower bound dependent on the field's directional spread. The influences that the orbital angular momentum and, for vector fields, the (spin or intrinsic) angular momentum due to polarization have on this lower bound are studied here for fields not constrained by the paraxial approximation