Bidirectional Optical Fiber for Cascaded Design

Hello Fatin,
As far as i understand your problem is very much related to the bidirectionality of the bidirectional fiber. I am not sure what exactly your design does but in my opinion i think it is regarding the bidirectional fiber. I would suggest you to go through the Optisystem tutorial and go through the Chapter 5. See if it does help. I will try posting the link of the same if i am able to find it.
Regards

Hello Fatin,
It is mentioned there that besides the typical global simulation parameters of OptiSystem, such as Bit rate, Samples per bit and Sequence length, there are two additional parameters that are very important when designing bidirectional systems: Iterations & Initial delay
Iterations force a component to calculate again until it generates, at the output ports, the Iterations number of signals.Initial delay forces a component to generate a null signal for each output port. Because the majority of OptiSystem components will not calculate if a signal is not available at the input ports, the Iterations and Initial delay parameter will help the user to avoid a situation in which the simulation will not perform because a component cannot find signals at the input port – and the system will be deadlocked. The concept of multiple iterations and delays is very confusing, because it does not have a physical meaning. It is a simulation technique and requires an understanding of the calculation scheduler of OptiSystem.
Please visit the link below. I hope it will help you.

Lesson 5: Bidirectional Simulation — Working with Multiple Iterations

Regards

Yes, you should go through the Bi-Directional Tutorial to understand how to simulate these designs. The problem here is a lack of simulation iterations and lack of initial delay. If you go to Layout parameters->Signals and check the Initial Delay box and increase the number of iterations to around 10 it will work.

Hello Fatin
You need to make the changes in the design based bidirectional fiber design tutorial and if you any other issue, I will try to sort out the problem.
Regards