超弹性形变线聚焦菲涅尔透镜的变焦性能研究

The variation of focal length with the oblique incidence angle of light is the main reason for reducing the performance of Fresnel lens solar concentrator. Based on the prism refraction theory，this paper analyzes the influence law of the inclined incidence angle on the focal length change of Fresnel lens by pointing out the optical reason for the focal length change. The method of adjusting the focal length by hyperelastic deformation，and the theoretical analysis based on the linear assumption under small deformation are put forward. The results show that when the deformation rate reaches 15%，the elongation of focal length is about 46.7%，which is less than 10% compared with the theoretical results. The results verify the correctness of the theoretical model，and provide a theoretical basis for the deformation and zoom of hyperelastic Fresnel lens.