This textbook provides all new updates to the field of quantum optics, covering the building blocks, models and concepts, latest results, details procedures and current milestone experiments. Places emphasis on three major applications: metrology, communication and quantum logic using modern techniques and terminology. Presents fundamental tests of quantum mechanics. Includes new trends and technologies in quantum optics, photon generation and detection, new results in sensing, and deeper coverage of quantum gates and logic, cluster states, wave-guides for multimodes, new quantum measures and results from quantum control.