focal surface的用法和樣例：
例句
- The key places for such manipulation are the back focal plane of the objective and the front focal plane of the substage condenser.
最關鍵的地方為物鏡的后焦面和載物台下聚光鏡的前焦面。 - The encircled-power method is introduced to define the beam width and real focal plane of focused sinh-Gaussian beams, thus their focal shift can be determined.
使用環圍功率法定義束寬和實際焦面，由此可以決定聚焦雙曲正弦高斯光束的焦移。
