A measurement based approach to extract nonlinearity in avalanche photodiode

In this work we present measurement approach and results for modeling the optical illumination dependent nonlinearity of avalanche photodiode. Pulsed RF technique was used for the measurement of small signal reflection coefficient of the photodiode. Pulsed optical stimulus was synchronized with the envelope of the pulsed RF signal using a synchronization circuit. Large signal model of the photodiode was derived from small signal measurement at different bias and optical conditions using a table based approach. Using CW optical power and CW scattering parameter measurement device heating limits the measurement to only 0.1 mW of optical power. However for practical use the photodiode is exposed to higher pulse amplitude and using the present approach photodiode was characterized to 1.3 mW of pulsed optical power.