Quantifying photodiode nonlinear characteristic induced by optical power and voltage

A new mathematical model, optical-power-dependent model R(P), is proposed by investigating the nonlinearity of modified uni-traveling carrier photodiodes (MUTC-PD). Benefiting from this model, the harmonic power and output 3rd order intercept point (OIP3) of a photodiode can be calculated. Considering a bias voltage shift of the photodiode caused by a large voltage swing effect, the R(P) mathematical model is expanded into a voltage-related one, which is the optical-power-and-voltage-dependent model, R(P,V). The calculate results of both mathematical models are completely in accord with simulation results.