Computers running on LIGHT?????

Just found an interesting article regarding advances in computer technology. Instead of using electric signals the whole system would run on light instead.

This poses the question though - can it run completely on light - no, not that i can fathom from the articles. There would still need to be some level of electronics involved but the logic circuits would use the light switching circuits to achieve much higher theoretical speeds than current silicon technology can achieve.

More information can be found here.