Interband Semiconductor Lasers and LEDs

This chapter discusses the operation of conventional diode lasers based on quantum wells and quantum dots as a function of emission wavelength. The recombination processes that control the threshold current density of the devices are described in detail, including recombination at defects, radiative, and Auger recombination. The high-speed modulation and spectral characteristics of semiconductor lasers are also discussed. It continues by illustrating why interband cascade lasers can outperform diode lasers at mid-infrared wavelengths and describing their design and operating characteristics in detail. On the short-wavelength side of the spectrum, the nitride lasers and the factors that limit their performance are discussed. In addition to lasers, the principles underlying light-emitting diodes (LEDs) are outlined, and the proposed mechanisms for improving the extraction of the light from high-index semiconductor materials are described. The chapter concludes with a discussion of the performance of semiconductor optical amplifiers designed to amplify a weak input signal.