Thank you all, I got the point. some functions actually are embeded by matlab code and of course, we cannot look inside.
And does any one who get the .osd files of assingment examples (https://optiwave.com/resources/academia/optisystem-lab-assignments/) which are run by OptiPerformer? I am playing with Optisytem 13 trial version and I want to look into all parameters of examples reather than some changable parameters.
Thank you!