Variable curvature mirror (VCM) can change its curvature radius dynamically and is usually used to correct the defocus and spherical aberration caused by thermal lens effect to improve the output beam quality of high power solid-state laser. Recently, the probable application of VCM in realizing non-moving element optical zoom imaging in visible band has been paid much attention. The basic requirement for VCM lies in that it should provide a large enough saggitus variation and still maintains a high enough surface figure at the same time. Therefore in this manuscript, by combing the pressurization based actuation with a variable thickness mirror design, the purpose of obtaining large saggitus variation and maintaining quite good surface figure accuracy at the same time could be achieved. A prototype zoom mirror with diameter of 120mm and central thickness of 8mm is designed, fabricated and tested. Experimental results demonstrate that the zoom mirror having an initial surface figure accuracy superior to 1/80λ could provide bigger than 36um saggitus variation and after finishing the curvature variation its surface figure accuracy could still be superior to 1/40λ with the spherical aberration removed, which proves that the effectiveness of the theoretical design.
Variable curvature mirror having variable thickness: design and fabrication
AOPC 2017: Space Optics and Earth Imaging and Space Navigation ; 2017 ; Beijing,China
Proc. SPIE ; 10463
2017-10-24
Aufsatz (Konferenz)
Elektronische Ressource
Englisch
Variable curvature mirror having variable thickness: design and fabrication [10463-62]
British Library Conference Proceedings | 2017