This 3-D (like a window) display has a huge array of
many,
many, many tiny lasers behind it. Here's how it
works:
Each crystal on the surface will vector light in many,
predictable directions depending on where the light is
coming from. To show a 2-D display one would shine
light
such
that all of each pixel/crystal have the same color on
all facets. To show a 3-D display, like a window, the
color
shown on facets the same direction show one image. A
facet, say, half a degree off show a slightly different
image.
By refracting three lasers in each facet of each crystal
you'll have a clear, bright, three dimensional display.