All optical logic gates using polarization switch

I was looking at this article
http://www.opticsinfobase.org/view_...-20332.pdf?da=1&id=222901&seq=0&mobile=no&org=
and it claims to make all optical logic gate using polarizing switches, the author claims that it is scalable, low power and
cascadable although he uses amplifiers (which I doubt would reduce the operational speed). But he is building AND,OR,NOR,NAND and even SR latch with these switches.
This PDF contains animated files below each figures to make understanding easier.
he claims very high speed of operation and ready industrial technology to make this optical gates.

I am still trying to understand his switch, but I want you to have a look and point out any shortcomings, as to why this is still not seen in real world.

if you are unable to open URL then I have uploaded the file.

Have you ever looked in an Edmunds Scientific Catalogue for the cost of high grade polarizers and beam splitters, or birefringent polarizers,?

It would make the 1st PC from Radio Shack at $3k look cheap.

apart from cost thing, the concept is working and may lead to super fast computers