Design-in Reliability for Modern Wavelength-division Multiplex (WDM) Distributed Feedback (DFB) InP Lasers

Due to the increasing channel density in WDM network, the reliability requirement of each channel has become increasingly stringent. To meet the stringent WDM reliability requirement, it is necessary to achieve stable threshold current and wavelength over time. In this paper, we study the design-in reliability of DFB InP lasers involving the controlling parameters such as p-metal contact, epitaxial regrowth interface, substrate quality and laser cavity length. We will discuss the influence of each parameter and physical mechanism. We demonstrate significant reliability improvement with incorporation of design and process optimization. We also discuss the correlation of reliability degradation and wavelength drift.