Degradation and Reliability

Abstract

The performance of semiconductor lasers can degrade during their operation. This degradation is usually characterized by an increase in the threshold current that is often accompanied by a decrease in the external differential quantum efficiency. The dominant mechanism responsible for this degradation is determined by one or several of the fabrication processes including epitaxy, device processing, and bonding. In addition, the degradation rate of lasers processed from a given wafer depends on the operating conditions, namely, the operating temperature and injection current. Although many of the degradation mechanisms are not fully understood, an extensive amount of empirical observations exists in the literature. These observations have allowed the fabrication of InGaAsP laser diodes with an extrapolated median lifetime in excess of 25 years¹ at an operating temperature of 10°C.