Hello faisel,There are optiwave fdtd,spice,bpm ,optifiberThey easily co simulate with optisystem.Just for information why would you need other software than optisystem.you can perform same task in optisystem which you do in others.If you wqnt to create your component ,tou can easily integrate matlab programme into optisystem.Even i have tried other similar softwares but couldnt find them user friendly .optisystem is eay to use and very user friendly for begginers rather than other softwares.