The reliability of silicon avalanche photodiodes for use in optical-fiber transmission systems

Thermal overstress tests on silicon avalanche photodiodes (APD´s) from two manufacturers have shown that APD´s, despite their complexity, can have adequate reliability for use in optical-fiber transmission systems in telecommunications networks. However, two failure mechanisms were observed on the APD´s from one manufacturer, namely increased surface leakage currents and localized premature breakdown, which would have caused either increased error rates or complete system failure. The results indicate that procurement specifications are required to guard against the use of unreliable APD´s in transmission systems, and procedures are recommended.