We are at the crossroads of a new epoch: the age of electronics is being replaced by the age of photonics. This book will introduce you to the fascinating development of photonics, avoiding complicated technical terminology and instead explaining the physical fundamentals in a clear way. Based on this, important developments such as the laser and its applications in industry, research and everyday life are described. Complicated physical properties and technical details are explained to the reader in an understandable way. The authors: Dr. Patrick Steglich is lecturer for photonics and optical technologies at the Technical University of Applied Sciences Wildau and scientist at the Leibniz Institute for Innovative Microelectronics IHP in Frankfurt (Oder). Katja Heise works as an editor in Berlin. As a trained political scientist and journalist, she specializes in translating complex technical topics into simple language. The authors live together with their son and two daughters in Berlin. This Springer essential is a translation of the original German 1st edition essentials, Photonik einfach erklärt by Steglich Patrick and Katja Heise, published by Springer Fachmedien Wiesbaden GmbH, part of Springer Nature in 2019.The translation was done with the help of artificial intelligence (machine translation by the service DeepL.com). A subsequent human revision was done primarily in terms of content, so that the book will read stylistically differently from a conventional translation. Springer Nature works continuously to further the development of tools for the production of books and on the related technologies to support the authors.