基于热变形的SOG型菲涅尔透镜优化研究

由硅胶-玻璃材料制成的SOG型菲涅尔透镜在温度变化时会产生热变形,从而对聚光性能产生影响。为了研究如何通过优化措施减弱热变形对透镜聚光性能的影响,在采用有限元方法模拟计算SOG型菲涅尔透镜热变形的基础上,根据均匀优化方法以及改进型补偿色散优化方法设计出两种菲涅尔透镜;并巧妙地将透镜热变形(包括整体翘曲变形和齿环侧面的自由变形)的变形量转化后导入光路理论模型中,解决了热变形参数难于在光路模型得到表达的难题;并成功模拟出变形前后透镜的光斑能量分布。模拟结果表明:SOG型透镜两种变形对均匀优化方法设计的透镜聚光有较大的影响。变形前后光效率相差可以达到10%。同时发现,透镜两种变形对聚光的影响刚好相反。综合两种变形后,热变形对聚光影响减少。从而得出了使用补偿色散的设计方法,可以有效地抵抗热变形对于透镜聚光的影响的结论。

Optimized and Research of Fresnel Lensbased on Thermal Deformation

The concentrating performance of SOG Fresnel lens, which is made of silicone and glass, is significantly affected by its thermal deformation including the warpage and the free deformation. In order to weaken the influence of the thermal deformation, two kinds of Fresnel lenses were designed through uniform optimization method and the improved dispersion compensation method, and the deformations of each lens were calculated through the finite element method. According to the simulation, it is found that the thermal deformation can be skillfully expressed as the optical model. Thus, the energy distribution of the concentrating spot of the deformed or the undeformed Fresnel lenses can be investigated, of which the consequence indicates that the influence of two types of deformations on the lens designed with uniform optimization method is rather different. The difference of optical efficiency is more than 10% between the deformed and the undeformed Fresnel lenses. Moreover, the effect of the two kinds of deformation on the concentrating performance is opposite, implicating the influence of thermal deformation can be weaken by the combination design of the warpage and the free deformation. The investigation also shows that the design method that compensates for dispersion is able to remarkably resist the the impact of thermal deformation.