Fundamentals of Optical Wireless Communications

Optical wireless communications (OWC) involves transmission and reception of signals where the carrier frequency lies in the optical domain. In radio frequency (RF)‐based communication systems, the carriers have wavelengths from kilometer to millimeter range; whereas in optical communications, the carriers have wavelengths in the micrometers and nanometer range. This chapter delves into these aspects of OWC and discusses these features in more detail. It talks about optical wireless channel characteristics along with source types and receiver configurations. The chapter shows that multipath fading, a property in RF communications channels, is absent for optical wireless channels. Multipath reflections, on the other hand, are present and the result is intersymbol interference (ISI) in high‐speed communications. The chapter distinguishes between two main source types, namely, lasers and light‐emitting‐diodes (LEDs), and discusses their common features and differences. Photo‐detectors and their related parameters are also discussed.