Book excerpt: Principles of Lasers and Optics, first published in 2005, describes both the fundamental principles of the laser and the propagation and application of laser radiation in bulk and guided-wave components. All solid state, gas and semiconductor lasers are analysed uniformly as macroscopic devices with susceptibility originated from quantum mechanical interactions to develop an overall understanding of the coherent nature of laser radiation. Analyses of the unique properties of coherent laser light in bulk and guided-wave components are presented together and derived from fundamental principles, to allow students to appreciate the differences and similarities. Topics covered include discussions on how laser radiation should be analysed, the macroscopic differences and similarities of various analyses, special techniques, types of lasers and setting up laser analyses. This text will be useful for first-year graduates in electrical engineering and physics and also as a reference book on analytical techniques.