Analytical Model for Obtaining the Ionization Rate Ratio of Mesa InAlAs Avalanche Photodiodes

We proposed a new analytical model to extract the effective ionization rate ratio k from the measured multiplication noise of Avalanche photodiodes (APDs). In this model, k was expressed as a function of the multiplication factor M. We extracted the effective k of the mesa-structured InAlAs APDs using this model. A measurement system that consisted of a low-noise differential preamplifier was developed for this purpose, leading to the measurements of the noise data, particularly in the region where it was small. APD noise data could be fitted to the curve based on this new analytical model better than with other analytical models over the wide range of M. The effective k in the region where M was small became appropriate using this model. The quantum efficiency of the APDs was also found to be reasonable compared with the results obtained using the other analytical models. (C) 2010 The Japan Society of Applied Physics