Impact of impulse response of avalanche photodiode to eye-closure penalty

Active elements are one of the key components of fiber-optic communication systems. In this paper, we discuss the influence of avalanche photodiode (APD) on the resulting eye-closure penalty as a parameter quantifying the degradation of transmission quality. Quality degradation due to the signal distortion and noise leads to the decreasing of the bit-error rate. The attention is focused on the numerical investigation of transient response of APD, which characteristics are comparable to the experiments. The behavior of APD response directly affect the inter-symbol interference of transmitted pulses and its impact is related to the eye-diagram closure.