A Review of IC Drivers for VCSELs in Datacom Applications

Vertical-cavity surface-emitting lasers (VCSELs) are an attractive choice for short-range optical interconnects (OIs) in datacom applications. As the limited bandwidth of VCSEL is the major obstacle to achieve higher data rates in these optical systems, significant effort has been made to develop efficient VCSEL drivers to increase data rate while consuming less power. We review the current state of the art in VCSEL driver design, including choices of semiconductor technology, modulation format, VCSEL configuration, and pre-emphasis techniques, with an emphasis on the challenges associated with VCSEL bandwidth limitations, nonlinearities, and thermal behavior. We illustrate the choices with simulations using a physics-based VCSEL model.