Study on the Nonlinearity of the Photodiode in a Microwave Photonic Link

In this paper, the nonlinearity of a microwave photonic link is studied considering the nonlinearity of the photodiode (PD). We build a new nonlinear model for a commercial PIN photodiode. The nonlinear characteristics between the Including-PD-Nonlinearity (IPDN) link and the Not-Including-PD-Nonlinearity (NIPDN) link are compared. Numerical studies indicate that the PD nonlinearity decreases the Spurious Free Dynamic Range (SFDR) Of the link by 0.05~1.8 dB. The result suggests that the nonlinearity of PD should be linearized for high SFDR links.