Hi Bilal,
There are a couple problems that I can see from the project files. (I can’t attach the working project files because they will not work with OptiSystem 7).
One problem is that the threshold current is in the 20 mA range, but your input current has an amplitude of 1 A.U. which in this context means 1 Amp. The amplitude is much too high for a physical device. The bias points are also too high since you start with 0.5 A.U. which converts to 500 mA.
The second problem is that in the Laser Measured project the bias current and modulation peak current of the Laser Measured Component need to be set to 0 to use the external source.
Regards