Theoretical approach to frequency response of resonant-cavity avalanche photodiodes

An efficient theoretical approach incorporating the mechanism of resonant absorption of the multiple reflected lightwaves is presented to model the frequency response of resonant-cavity (RC) avalanche photodiodes (APDs). Although the theoretical expressions are derived with respect to the RC separate absorption, charge and multiplication (SACM) structure, they are actually very general and can be applied to other RC APD structures and many non-RC APDs. As an example, the theoretical approach is applied to the InGaAs/InAlAs RC SACM APD. The computation results of -3 dB bandwidth based on the present theoretical approach are consistent with the experiment.