Techniques for designing hybrid diffractive optical systems

摘要

Abstract: The authors analyzed techniques for designing lenses consisting of conventional reflective or refractive elements used in conjunction with binary optical elements (BOEs), and reviewed the use of BOE correctors in systems with both rotational and bilateral symmetry. These systems add a large number of degrees of freedom, such that almost any arbitrary wavefront shape can be obtained. For this reason, automatic optimization with BOEs requires special considerations; especially, tilted or decentered systems, wide-waveband systems, or wide field-of-view systems. If caution is not exercised, one can easily consume large amounts of expensive cpu time only to converge on nonoptimal dead-end solutions. A typical situation that occurs is the convergence upon a solution where the performance is diffraction limited at the finite number of defined field points, but strongly aberrated at field points in between. The key to converging on an optimal solution is the proper use of user defined constraints. The authors studied how to select which BOE coefficients to vary and how to choose field points in order to increase the probability of converging on optimal solutions.!7