Measurement and Modeling of a High-Linearity Modified Uni-Traveling Carrier Photodiode

The third-order intermodulation distortions of an InGaAs-InP charge compensated modified uni-traveling carrier photodiode (PD) are characterized using a two-tone setup. At 310-MHz modulation frequency, the third-order local intercept point (IP3) reaches 52 dBm and remains above 35 dBm up to 21GHz. Based on experimental results for the dependence of responsivity and PD capacitance on bias voltage and photocurrent, we use a simple equivalent circuit model to simulate the frequency characteristics of the intermodulation distortions.