數值孔徑 (Numerical Aperture, NA) 計算 Na = \frac {D} {2f} 解析度 (Resolution) 計算 Resolution = \frac {\lambda}{2NA} 截止頻率計算 f_0= \frac {D}{2 \lambda f} f_0= \frac{1}{\lambda} \frac{D}{2f} f_0= \frac{NA}{\lambda} ``` 解析度與截止頻率關係 ---------- ``` Resolution = \frac{1}{2f_0} = \frac{\lambda}{2NA} ```