This book on experimental physics is the fourth volume of the long-awaited elaboration of the extremely popular lectures by Joachim Heintze. This volume deals with the fundamentals of wave phenomena and optics, as taught in the experimental physics courses in the Bachelor's degree program at the university. The author's love for physics and for exciting and historical experiments is evident throughout the book and can be felt in every chapter. Here you will find all the topics relevant to the Bachelor's and minor studies in physics presented in a clear and particularly understandable manner, accompanied by numerous illustrations. Exercises with detailed solutions facilitate exam preparation. Whether physics is your major or a minor subject, you will benefit from the clear explanations and engaging presentations in any case.