Time-domain simulation analysis of avalanche photodetectors

The avalanche photodiode (APD) avalanche multiplication impulse response is evaluated by solving the time-varying rate equations in the time domain. The device simulation allows the motion of the carriers under the influence of the active region's electric field. The inclusion of carder motion in the model replaces the undesired divergence terms which cause errors due to the numerical differentiation. An application is given to study the effect of the APD bias on the device multiplication impulse response and bandwidth.