KINOFORM DESIGN WITH AN OPTIMAL-ROTATION-ANGLE METHOD

Kinoforms (i.e., computer-generated phase holograms) are designed with a new algorithm, the optimal-rotation-angle method, in the paraxial d omain. This is a direct Fourier method (i.e., no inverse transform is performed) in which the height of the kinoform relief in each discrete point is chosen so that the diffraction efficiency is increased. The optimal-rotation-angle algorithm has a straightforward geometrical int erpretation. It yields excellent results close to, or better than, tho se obtained with other state-of-the-art methods. The optimal-rotation- angle algorithm can easily be modified to take different restraints in to account; as an example, phase-swing-restricted kinoforms, which dis tribute the light into a number of equally bright spots (so called fan -outs), were designed. The phase-swing restriction lowers the efficien cy, but the uniformity can still be made almost perfect.