Some physical considerations on digital optical computing

Since optical communication is preferable for establishing connections exceeding a certain critical length, for large system sizes the beneficial use of normally conducting wires for the shortest connections becomes an edge effect and can be ignored. This suggests that the performance and cost of an all optical computer might not be much inferior to an optimal hybrid alternative. We argue that for applications for which high bit repetition rates are useful despite large propagation delays, it might make sense to contemplate the construction of an optical digital computer.