We also took some measurement of PD spectrum.
Attached figure 1 shows the measurement of CC1 PD noise after demodulation for different incident power. In this figure, op-amp LMH6624, R1 1.1kOhm, R2 13kOhm are used.
We could see that noise becomes to be shot noise limited when laser power reaches around 300uW. Therefore, I confirmed that electronic noise was still limiting in this case. Then I checked again the simulation, which shows the noise is limited by the resistor. However, according to the simulation, shot noise should start to limit after laser power reaching 3mW.