Single metalens focuses all colors of the rainbow in one point;

[steve001]

With so many nano elements, it wouldn't surprise me to see it cause a great deal of interference patterns. Some constructive and others destructive.

Perhaps so.

 

[steve001]

Edmund Optics carries flat laser optics. But there don't seem to be the type shown in the article.

https://laserpointerforums.com/f49/flat-lenses-edmund-optics-98664.html