Large signal modeling of avalanche photodiode for correction of optical power dependent nonlinearity

In this research work we will discuss the large signal modeling of the avalanche photodiode (APD) and use of the large signal model for nonlinearity error correction in case of large signal optical pulse excitation. Measurements were carried out using pulsed RF measurement to extract small signal equivalent circuit parameters of the device at different bias and optical conditions. Pulsed RF measurement is necessary to characterize APDs because of limited heat dissipation power of the chip. Using cw optical signal the measurement is restricted within 0.1 mW of optical power. Using pulsed RF approach the photodiode was characterized for its practical range of up to 1.3 mW of peak optical power. Photodiode large signal model was implemented in a harmonic balance simulator, and was verified by measurement of nonlinearity error using large signal optical stimulus.