I forgot to explain the Initializer in my previous post. It is really the key component along with the Optical Ring Controller.
The Initializer allows you to start a ring simulation with an initial field, in subsequent iterations it will propagate the optical signal around the loop indefinitely. That is unless of course you use a Optical Ring Controller, which will tell the simulator to stop the calculation after a number of loops. There is also a convergence tool you can use that will stop the simulation when the signal reaches steady state, however in this case the signal is constantly changing, so I chose to control the number of loops explicitly.
Regards