Hello Umer,
As far as optical sensors are concerned i seem to agree with Aabid Baba. Surely we can design optical sensors in Optisystem making the use of fiber bragg grating. I would suggest you to refer to the link provided by Aabid Baba. It nicely & briefly explained how we can make use of gratings to ensure design of an optical sensor.
I hope this is helpful.
Regards
Burhan