How are phosphorescent displays used as monitors?
Storage CRT's are a different thing. 

The ongoing storage glow is continually powered by electrons - it is not some property of the phosphorescent material itself. So outside of a storage vacuum tube, the material is just ordinary phosphor and has no special "erase" property.

With a phosphorescent material, you just need to keep re-writing the image with your laser. This is entirely doable, and should be wickedly good.

You do need to use vector (line) graphics not raster scan type images.