Method for designing a refractive or reflective optical system and method for designing a diffraction optical element

摘要

In the design of a lens system, lens parameters are determined by minimizing a merit function which is a sum of squares of ray aberrations or wavefront errors at many sampling points. Prior methods often select the parameters which give very narrow tolerances to production errors. The small tolerance increases the difficulty of production. In order to increase the tolerance, states which allot errors ±δ to some chosen parameters are considered. Merit functions corresponding the error-allotted states are made. An integrated merit function is produced by adding the error-allotted merit functions to the non-error allotted normal merit function. Parameters are determined by minimizing the integrated merit function. The optimized parameters will give wider tolerances for the error-allotted parameters.;DOE (diffraction optical element) design includes the steps of considering error-allotted states S1, S2,··· in addition to a non-error state So, making merit functions E1, E2, ··· for S1, S2··· besides Eo for So, defining an integrated merit function E=ΣwkEk by multiplying the merit function with weights and summing up, minimizing the integrated merit function and determining optimum variables for the DOE.