研究了利用大孔径折射透镜对太赫兹波进行聚焦时产生的焦移效应。焦移效应所引起的焦点位置偏差会对太赫兹系统的成像或测量质量产生不利影响。通过理论计算和有限元分析仿真，研究并讨论了与透镜孔径、焦距和工作频率有关的焦移参考值。当使用商用透镜时，实际焦点位置需要通过焦移效应来确定，以保证太赫兹系统的工作效率。对于定制透镜的设计，焦移需要根据工作频率，在焦距的设计中进行补偿。这两个途径可以保障太赫兹系统的良好性能。

大视场、低成本、高性能天文望远镜是当前研究和开发的热点。基于像差平衡原理，在正入射施密特矫正板基础上推导出斜入射反射式施密特矫正板方程，针对焦距1 700 mm，成像视场角4°，波段为0.4 μm～0.9 μm，F数为4.25的光学系统，求解出施密特矫正板方程，并作为初始结构参数代入Zemax软件进一步优化。设计结果表明，在全视场范围内，该系统在奈奎斯特频率100 lp/mm处的调制传递函数MTF大于0.35，畸变小于2.5%，成像质量达到了衍射极限。优化设计后施密特矫正板与最近球面最大偏差为0.005 mm，采用特制的补偿器结合干涉仪可完成面形高精度检测。该施密特系统的设计为大视场、宽波段天文望远镜的开发提供了参考。

We implemented a stitching swing arm profilometer (SSAP) test for the inner and outer regions of a large aspheric surface with a short arm. The SSAP was more capable of improving sampling density of surface and was less sensitive to system error, like vibration noise and air-table noise. Firstly, a calculation model was built to evaluate the sampling density of the SSAP test. Then, sensitivity to system noise was tested when different lengths of arm were used. At the end, an experiment on a 3 m diameter aspheric mirror was implemented, where test efficiency was promoted, and high sampling density was achieved.

Myopia has become a noteworthy issue due to the increasing use of our eyes. We propose a continuous power variation vision-training device based on Alvarez lenses with the power ranging from 10 D to +2 D. First, we introduce the principle of Alvarez lenses and the evaluation method of dioptric power and astigmatism. Then, we optimize the optical system described by Zernike polynomials. Finally, we analyze the distributions of dioptric power and astigmatism with the overall surface analysis and fields of view (FOVs) analysis. The results show that the optical performance of an optimized system can meet the requirement within a 40° FOV.