concave lens 是什么意思

	凹透镜。

	concave: adj. 凹的，凹面的 (opp. convex)。 n ...
	lens: n. (pl. lenses) 1.透镜；一组透镜。 2 ...

a lens such that a parallel beam of light passing through it is caused to diverge or spread out
同义词：diverging lens,

	1.	Just as a double convex lens enlarges , so a double concave lens reduces 正象双凸透镜可以放大那样，双凹透镜也可以缩小。
	2.	Some are flared ? that is , thicker at the rim than in the center , like a concave lens 有些呈喇叭形即边缘较中心厚，类似凹透镜。
	3.	We fabricated a large computer - generated holography on a concave lens surface to test the convex secondary mirrors surface 在凹透镜表面上制作出了用于凸非球面检测的曲面全息图。
	4.	We demonstrate experimentally the technique to fabricate large does in the thick film on a concave lens ( mirrors ) surface with precise alignment by using the strategy of exposure twice 采用两次曝光的方法在凹透镜表面上厚光刻胶中制作衍射光学元件。

concave lens是什么意思