Hi Burhan NUm Mina llah,
I guess there is such provision of interfacing simulink becuase i had seen a link mentioning so.
Currently i guess we can only interface Matlab modules with optisystem 14 if you check the optisystem library there is only Matlab interface in the library.
One thing i can tell you is that if you are currently working on Matlab , you have an optical communication library there too (newer version). If you could somehow translate your simulink module to Matlab module, it can prove helpful for you. Hope it helps.
Best regards