Dear Editor Freeform optical surfaces have no axis of rotational invariance,thus providing more design degrees of freedom(DoFs)than conics and aspheres1,2.The additional DoFs can be used for aberration correction in c...Dear Editor Freeform optical surfaces have no axis of rotational invariance,thus providing more design degrees of freedom(DoFs)than conics and aspheres1,2.The additional DoFs can be used for aberration correction in compact folded imaging systems3–6 and for increasing efficiency and irradiance uniformity in illumination systems7–9.However,given their surface form complexity,freeform optics remain challenging to manufacture,test,and assemble1,9.Reference structures(RS)–physical features designed and fabricated in addition to the optical surfaces–are required to define a common coordinate system(CS)during the manufacturing process chain10–13.We present the conclusions of a literature and industry survey on the effective implementation of RS.We then demonstrate the benefits of an automated tool for generating CAD models with accurate NURBS freeform surfaces and effective RS to for use in manufacturing and metrology.We conclude with the design of a test framework for further evaluation and comparison of the effectiveness of various types of RS.展开更多
基金supported by the industry members of the Center for Freeform Optics(CeFO)and the National Science Foundation(IIP-1822049 and IIP-1822026,EEC-2310640,EEC-2310681).
文摘Dear Editor Freeform optical surfaces have no axis of rotational invariance,thus providing more design degrees of freedom(DoFs)than conics and aspheres1,2.The additional DoFs can be used for aberration correction in compact folded imaging systems3–6 and for increasing efficiency and irradiance uniformity in illumination systems7–9.However,given their surface form complexity,freeform optics remain challenging to manufacture,test,and assemble1,9.Reference structures(RS)–physical features designed and fabricated in addition to the optical surfaces–are required to define a common coordinate system(CS)during the manufacturing process chain10–13.We present the conclusions of a literature and industry survey on the effective implementation of RS.We then demonstrate the benefits of an automated tool for generating CAD models with accurate NURBS freeform surfaces and effective RS to for use in manufacturing and metrology.We conclude with the design of a test framework for further evaluation and comparison of the effectiveness of various types of RS.
