ABSTRACT
Vertical-cavity surface-emitting lasers (VCSELs) are a type of semiconductor laser with a very short cavity length, and with laser beam emission in the vertical direction, perpendicular to the wafer. VCSELs can be directly modulated for digital and analog communications. VCSELs have replaced edge-emitting lasers in commercial applications such as Gigabit Ethernet and Fibre Channel. This chapter focuses on some aspects of current and a future application of VCSEL in short-reach optical interconnects. Active optical cable (AOC) links for short-reach computer and consumer applications are increasingly based on VCSELs operating in the near-infrared spectral range. The chapter describes the high-speed performance and the bandwidth limitations of VCSELs, including laser dynamics, the electrical parasitics, and the carrier dynamics. Optical injection locking (OIL) of semiconductor lasers was first demonstrated in 1976 using edge-emitting Fabry–Perot lasers, in 1991 using distributed feedback lasers (DFBs), and in 1996 using VCSELs. The chapter focuses on several theoretical models that attempted to explain the mystery of injection-locked lasers.
