knotimpressed parent
I wonder if the requirement to rotate the target is inherent, or if it could be optimized away eventually?
I suspect this was an easy way to test it without having to build a rotatable optical bench.
A practical device may be an array of light sources and telescopes on a rotating mount or a set of moveable mirrors that achieve the same effect.
If it is required, then in a real application you could just rotate the laser array instead.
I also wonder about the requirement for the letters to be made of reflective material.