Nonlinear Characteristics of Uni-Traveling Carrier Photodiode With InGaAs/GaAsSb Type-II Multiple Quantum Wells Absorber

The linearity of high power photodetectors is the limiting factor to the dynamic range performance of analog optical links and microwave photonics applications. In this work, we characterized the third order intermodulation distortion (IMD3) of a uni-traveling carrier photodiode with InGaAs/GaAsSb type-II multiple quantum wells absorber. The 10 μm diameter photodiode shows a third order output intercept point of 36.6 dBm at 200 MHz and 12.9 dBm at 25 GHz, under reverse bias of -5 V and photo current of 15 mA. Combining with the measured device parameters, an equivalent circuit model based simulation is carried out, and the general trend of the simulated IMD3 is consistent with the measurement results. By separately involving the nonlinear mechanisms, the source of the nonlinearity is studied in detail.