QUALITY IMPROVEMENT OF SYMMETRICAL-INTENSITY BEAMS PROPAGATING THROUGH PURE PHASE PLATES

Quality improvement by using pure phase plates through which nonideal beams are made to propagate is analysed. An explicit analytical expression is given for the minimum value (highest quality) of the beam quality parameter of symmetric-intensity beams propagating through this class of transmittances. Moreover, the phase function that should be employed to achieve such a limit (best) quality value is determined. Some consequences for Hermite-Gauss laser beam modes are also obtained.