A review of the reliability of optical detectors

The authors review work at British Telecommunications Research Laboratories (BTRL) on photodetector reliability. These commercially available components are all designed for telecommunications applications, and include mesa and planar InGaAs PINs, germanium avalanche photodiodes (APDs) and InGaAs APDs. A description is given of the types of photodiode tested, followed by the results of life-testing and failure analysis. It has been demonstrated that planar PINs are superior to mesa PINs, and that planar InGaAs PINs can have very low failure rates. III-V avalanche photodiodes have been extensively life-tested and a number of failure mechanisms have been detected. However, it has been shown that these components can also have an acceptable reliability. Life-tests on germanium APDs have identified failure modes occurring in devices from one vendor, but devices from a further two vendors have shown stable performance, albeit in life-tests with a low acceleration factor.