A simplified non-Gaussian approach to digital optical receiver design with avalanche photodiodes: experimental

Detailed experimental measurements of various digital receiver parameters taken on a receiver using a low noise silicon avalanche photodiode are compared with simple theories that incorporate Gaussian and non-Gaussian models for the probability distribution functions for the avalanche gain. The authors analyze the salient aspects of the theories, particularly those parameters that give results different from the Gaussian approximation, and those parameters that are readily extracted from the theory (e.g., the influence of background current due either to dark current or to imperfectly extinguished light sources). Experiments were performed in which a receiver was characterized for bit error rate (BER) and optimum gain as the optical power at a modulation rate of 10 Mb/s (NRZ) was varied and as additional background light was allowed to fall on the detector. Excellent agreement with the author's newly developed simplified approximation to the non-Gaussian theory for receiver sensitivity (ibid., vol.9, p.1019-26, Aug. 1991) is obtained.<
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