ABSTRACT
This chapter discusses the principles of laser diodes. The mechanisms for gain, current injection, radiative recombination and non-radiative recombination (Auger recombination) are discussed. The dependence of gain on injected carrier density and current is described. Index-guided and gain-guided laser designs and their fabrication are described. The principle of operation, design and characteristics of single-wavelength distributed feedback lasers and tunable lasers needed for optical communication and sensor applications are described. The gain and operation of quantum cascade lasers which operate on intraband transition in a quantum well are described. The design and operation of lower-dimensional lasers such as quantum well, quantum wire and quantum dot lasers, and nanostructure lasers are discussed.
