Akima Hisanao, Yoshida Takaho
Central Research Laboratory, Hitachi, Ltd, 1-280 Higashi-Koigakubo, Kokubunji-shi, Tokyo 185-8601, Japan Research Institute of Electrical Communication, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan.
Central Research Laboratory, Hitachi, Ltd, 1-280 Higashi-Koigakubo, Kokubunji-shi, Tokyo 185-8601, Japan
Microscopy (Oxf). 2014 Aug;63(4):325-32. doi: 10.1093/jmicro/dfu010. Epub 2014 Apr 16.
A method for measuring large aberrations up to second order (defocus, 2-fold astigmatism and axial coma), which uses a through-focus series of Ronchigrams, is proposed. The method is based on the principle that line-focus conditions in Ronchigrams can be locally detected and low-order aberrations can thereby be measured. The proposed method provides auto-tuning of large low-order aberration; in particular, iterative aberration measurement and correction reduce low-order aberrations from several thousand nanometers to less than a few hundred nanometers, which can be handled by conventional fine-aberration tuning methods.
提出了一种用于测量高达二阶的大像差（散焦、两倍散光和轴向彗差）的方法，该方法使用一系列通过焦深的龙奇图。该方法基于这样的原理：龙奇图中的线聚焦条件可以在局部被检测到，从而可以测量低阶像差。所提出的方法实现了大低阶像差的自动调谐；特别是，迭代像差测量和校正将低阶像差从几千纳米降低到小于几百纳米，这可以通过传统的精细像差调谐方法来处理。
