a concave reflector used to produce a parallel beam when the source is placed at its focus or to focus an incoming parallel beam
双语例句
The off-axis parabolic mirror is developed for the Singaporean synchrotron radiation light source development in this paper,in cluding Parabolic mirror fabrication and testing. 大离轴抛物面镜的加工与检测是当今光学加工的热门课题。
