WAVE-FRONT QUALITY OF OPTIMIZED DIFFRACTIVE LENSES

Diffractive lenses can be designed using optimization techniques, such as radially symmetric iterative discrete on-axis (RSIDO) encoding. Th e wavefront quality of such lenses is evaluated using the point spread function and the modulation transfer function. We find that the wavef ront quality is highly dependent on the particular merit function used for optimization. It is found that an optimization based on the diffr action efficiency can lead to a significant degradation in wavefront q uality. Whereas optimization based on an image-quality merit function does not lead to a strong decrease of diffraction efficiency.