透镜的分辨率极限 Ro 0.6122 M nsina nsina.数值孔径(numerical aperture,NA) Visible Light:~6000 A X-rays: λ0.5-2.5A Electrons: λ~0.05 17透镜的分辨率极限 17 nsin: 数值孔径(numerical aperture, NA)