Diffractive optical element (DOE) can be used for beam smoothing. The phase
of the DOE is generally designed by the optimization algorithm. In optimiz
ation, the intensities of the sampling points on the focal plane are optimi
zed to be consistent with the required beam smoothing, but the other points
are not consistent with such a requirement. In this paper. a new method wi
th a more restrictive way in the optimization is proposed to design the DOE
for realizing a true beam smoothing. The result obtained by this new metho
d is that the intensity of any point on the focal plane is fully filled wit
h the required demand, besides the used sampling points in the optimization
. (C) 2001 Published by Elsevier Science B.V.