MOMENT DEFINITION OF THE POINTING STABILITY OF A LASER-BEAM

A new definition of the pointing stability of a laser beam is proposed . It is derived from the superposition integral between the optical fi eld and a misaligned version of itself. This approach permits the char acterization of the pointing stability with a single number, while tak ing into account the intensity and phase features of the beam. This po inting stability criterion is invariant under propagation and can be r elated to the moment definitions of beam size, divergence, and quality . The definition is also suggestive of an experimental measurement pro cedure.