Laser (video)

A new video by Clifford V. Johnson:

More like this

I thought that this was really well done. I think with only a dozen players, much of what's going on is lost. But I guess with many more players it would be too confusing.

The video is pretty cool and technically correct. My only comment is that they say in the beginning of the video that laser light is more focused than other light.

I have always been told that laser light is directionally coherent,with very low divergence. And that in order to focus a laser, or any light, a lens is needed. Due to the directional coherence it is easier to focus a laser, but that a laser is not "focused" until directed by a lens.

My pet peeve is someone saying they will "focus like laser" on a task. Which is a meaningless statement that shows no understanding of what a laser is.

Can one of the optics scientists correct me if I am wrong about my understanding?