1. Preface. 2. Physical principles of the operation of semiconductor lasers. 3. Basic techniques for fabricating semiconductor lasers. 4. The design and basic characteristics of semiconductor lasers. 5. Review of the structures and properties of Fabry Perot cavity junction lasers. 6. Structures of distributed feedback lasers. 7. Dynamic properties of junction lasers and methods for improving their frequency discrimination. 8. Thermal effects occurring in semiconductor lasers. 9. Principles of modelling the physical phenomena in junction lasers. 10. Reliability of LEDs and junction lasers. References. Subject Index. List of main symbols. List of abbreviations.