Math Is Fun Forum

This idea is not so new. It has been arround since 2006.

See here:

http://www.cs.ubbcluj.ro/~moltean/optical

I cite from their 2006 paper:

"In this paper we suggest the use of light for performing useful computations. Namely, we propose a special device which uses light rays for solving the Hamiltonian path problem on a directed graph. The device has a graph-like representation and the light is traversing it following the routes given by the connections between nodes. In each node the rays are uniquely marked so that they can be easily identified. At the destination node we will search only for particular rays that have passed only once through each node. We show that the proposed device can solve small and medium instances of the problem in reasonable time."