laser beam focusing

A team of physicists in the us has created an infrared laser beam at a point in mid air, by focusing a UV laser onto a tiny volume of oxygen molecules.

美国的一个物理学家团队通过将一束紫外激光聚焦于一小块氧分子中，发明了一种聚焦于半空中一点的红外激光束。

Pointing and focusing a laser beam on a target that is rocketing skyward at thousands of miles per hour is no easy task, but the Airborne laser is uniquely able to do the job.

对于飞行速度每小时数千英里的目标进行激光束瞄准和聚焦并不容易，但机载激光器是唯一能够完成这项工作。

The study of the focusing characteristics of laser beam is an important content in the study of laser propulsion technology.

激光束聚焦性能研究是激光推进技术研究中的一个重要内容。