The receiver sensitivity can be defined as the minimum average
optical power at given BER. There is a lot of parameters which contribute to the optical receiver sensitivity by following equation:
Optical sensitivity is given by:
Sen (dBm) = 10log[(OMA*(re+1))/((re-1)*2000)]
– re is the extinction ratio of the received optical signal
– OMA is the optical modulation amplitude:
OMA = Ipp/ρ (in μW)
– ρ is the photodetector responsivity (A/W)
Hope it can be useful for you
Ref: Accurately Estimating Optical Receiver Sensitivity – MAXIM intergrated