This book offers an overview of the state-of-the-art of visible light communication systems across emerging areas of increasing importance within the field. It is divided into two parts, with the first describing the latest developments in data communication using VLC technologies. It includes the fundamental mechanics of the semiconductor light-emitting diodes (LEDs) used in academic and commercial systems, areas of high-speed circuit design including circuit diagrams and small-signal analysis. Exotic modulation formats and digital signal processing including machine learning architectures are then covered before the book looks at emerging areas within the VLC research community, including colour balancing and colour-based modulation. The second part of the book looks at applications that do not consider indoor data communication in general, such as localisation/positioning, sensing and the intelligent transport systems paradigm. Finally, the completely new area of oxygen sensing is also included with the aim of inspiring researchers to test news fields and apply ideas across domains. Visible Light is aimed at new researchers entering the VLC domain, particularly at the PhD stage, or those wishing to explore new areas within it, and readers should be comfortable with undergraduate-level mathematics and physics to make the most of the derivations and descriptions written throughout the book. It will provide researchers with a solid summary of the global progress in VLC systems that can be used to generate new ideas and advancements in the field. Key Features A new approach to VLC literature: describing both communications and new applications Enables interdisciplinary new approaches to research and industry through the collection of ideas from separate disciplines that researchers and industrialists may not be aware of Discussion of technological enablers from semiconductor materials, through to devices, circuits, systems and applications: the first book on the subject to do so The first book that brings healthcare sensing to the general VLC community, potentially adding significant value to the research community through ideas generation and awareness of literature A reference text for researchers and industrialists to discover immediately any of the key advances in the field from any subdomain, enabling off-the-shelf knowledge generation