'Prof. Nisoli's book is an excellent introduction for masters or graduate level students wishing to learn more about the physics underlying semiconductor lasers and light emitting diodes. In the first half of the book there is a thorough, modern discussion of semiconductor physics, optical properties and band theory, with an interesting section on quantum wells. The final three chapters are a detailed and comprehensive discourse on LEDs, semiconductor lasers and low-dimensional lasers. I shall certainly be recommending my students to read this book as part of their studies.' Robert A. Taylor, University of Oxford