Design of diffractive optical element for true beam smoothing

Diffractive optical element (DOE) can be used for beam smoothing. The phase of the DOE is generally designed by the optimization algorithm. In optimization, the intensities of the sampling points on the focal plane are optimized 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 with 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 method is that the intensity of any point on the focal plane is fully filled with the required demand, besides the used sampling points in the optimization.