Design method for an off-axis reflective anamorphic optical system with aberration balance and constraint control
| Autor: | Wang Liping, Yue Wu, Bo Yu, Xu Zhang, Chunshui Jin, Yu Jie |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
Physics
business.industry Extreme ultraviolet lithography 01 natural sciences Atomic and Molecular Physics and Optics Numerical aperture 010309 optics Root mean square Projection (relational algebra) Error function Optics 0103 physical sciences Simulated annealing Ray tracing (graphics) Electrical and Electronic Engineering business Adaptive optics Engineering (miscellaneous) |
| Zdroj: | Applied Optics. 60:4557 |
| ISSN: | 2155-3165 1559-128X |
| DOI: | 10.1364/ao.427713 |
| Popis: | This paper proposes a design method for an off-axis reflective anamorphic optical system (ORAOS). This method first applies vector aberration theory to establish a mathematical model to balance the aberration of an ORAOS. It then builds the error function of structural parameters and constraints through spatial ray tracing and grouping design. Next, it introduces automatic adjustment of weight factors for dynamic balance of aberrations and constraints. A particle swarm simulated annealing algorithm is used to iteratively calculate the initial structure of the ORAOS. Finally, we use an extreme ultraviolet (EUV) lithographic projection objective with off-axis six-reflective anamorphic mirrors ( β x = 1 / 4 , β y = 1 / 8 ) as an example to verify the effectiveness of this method. We obtain an EUV lithographic anamorphic objective with a numerical aperture of 0.55 and a root mean square wavefront error better than 1 / 30 λ ( I ^ ≫ = 13.5 n m ). |
| Databáze: | OpenAIRE |
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