  The transverse spatial attributes of an optical beam can be decomposed into
the position, momentum and orbital angular momentum observables. The position
and momentum of a beam is directly related to the quadrature amplitudes, whilst
the orbital angular momentum is related to the polarization and spin variables.
In this paper, we study the quantum properties of these spatial variables,
using a representation in the Stokes-operator basis. We propose a spatial
detection scheme to measure all three spatial variables and consequently,
propose a scheme for the generation of spatial Stokes operator squeezing and
entanglement.
