Abstract
The chapter covers In P-based laser diodes (1300-1650nm wavelength range) deployed as transmitter devices in today's optical communication systems. Only discrete directly modulated devices are considered in this chapter which is followed by two other laser-related articles dealing specifically with ultra-fast and wavelength-tunable devices. In the first part, a description of basic laser structures and technology, of relevant gain materials and their impact on lasing properties, and of fundamental characteristics of Fabry-Pérot devices will be presented. The second part is devoted to single-wavelength lasers focusing on design rules and various implementations. Essentially, distributed feedback (DFB) devices are treated but other options such as the so-called discrete mode laser diodes will also be outlined. In the third part, surface-emitting laser diodes are addressed including vertical cavity surface-emitting lasers (VCSEL) and horizontal cavity DFB structures design ed for surface emission.