Optimization design method of soft x-ray multi-element optical system with two-dimension field light source for large aperture imaging

Soft x-ray multi-element optical system with two-dimension field light source is widely used for synchrotron radiation, microscope, etc., and optimization design method of this kind of optical systems with large aperture imaging is studied in this paper. Since aberration analysis method is the basis for studying it, and thus, we firstly derived fifth-order aberration expressions of soft x-ray multi-element optical system with two-dimension field light source; secondly, the aberration modification expressions due to aperture-ray coordinates with second-order accuracy are obtained, and the extrinsic aberration calculation expressions are derived by the reverse optical path; then, aberration expressions derived in the above are validated and have a satisfactory calculation accuracy. In addition, evaluation function expression of imaging performance of this kind of optical systems is established, and then applying self-adaptive variation probability genetic optimization algorithm to solve it to obtain the structure parameters of optical system. Finally, they are applied to optimize the aberration of a soft x-ray multi-element optical system with two-dimension field light source, and comparing and analyzing the imaging results before and after aberration optimization; these results verify the effectiveness of the optimization method discussed in this paper.