This textbook employs a pedagogical approach that facilitates access to the fundamentals of Quantum Photonics. It contains an introductory description of the quantum properties of photons through the second quantization of the electromagnetic field, introducing stimulated and spontaneous emission of photons at the quantum level. Schroedinger's equation is used to describe the behavior of electrons in a one-dimensional potential. Tunneling through a barrier is used to introduce the concept of non locality of an electron at the quantum level, which is closely-related to quantum confinement tunneling, resonant tunneling, and the origin of energy bands in both periodic (crystalline) and aperiodic (non-crystalline) materials. Introducing the concepts of reciprocal space, Brillouin zones, and Bloch's theorem, the determination of electronic band structure using the pseudopotential method is presented, allowing direct computation of the band structures of most group IV, group III-V, and group II-VI semiconductors. The text is supported by numerous numerical calculations that can be repeated by the student. The book includes an extensive treatment of the time duration of tunneling. The non-local nature of quantum mechanical states is further developed by the proof of Bell's theorem and an in-depth discussion of its implications for experimental phenomena like quantum tunneling and quantum entanglement. The entangled quantum photon pair is the workhorse for exploring the fundamental non-locality of quantum mechanics, as well as important applications such as quantum cryptography. Further, the book presents the generation of entangled photon pairs by spontaneous parametric downconversion in detail using operators of the quantized photonic field. The physics of laser action is presented using the quantum photonic basis of spontaneous and stimulated emission, highlighting the limits of Maxwell's equations in describing quantum behavior. Further, the book shows how the quantum confinement of electrons leads to reduced threshold current on the macroscopic level. Quantum cascade and interband cascade laser structures are analyzed using methods developed in earlier chapters to show how band structure engineering can be applied to access photon emission energies that cannot be achieved using conventional materials.

Photonics is the discipline of electrons and photons working in tandem to create new physics, new devices and new applications. This textbook employs a pedagogical approach that facilitates access to the fundamentals of quantum photonics. Beginning with a review of the quantum properties of photons and electrons, the book then introduces the concept of their non-locality at the quantum level. It presents a determination of electronic band structure using the pseudopotential method, enabling the student to directly compute the band structures of most group IV, group III-V, and group II-VI semiconductors. The book devotes further in-depth discussion of second quantization of the electromagnetic field that describes spontaneous and stimulated emission of photons, quantum entanglement and introduces the topic of quantum cascade lasers, showing how electrons and photons interact in a quantum environment to create a practical photonic device. This extended second edition includes a detailed description of the link between quantum photon states and the macroscopic electric field. It describes the particle qualities of quantum electrons via their unique operator algebra and distinguishable behavior from photons, and employs these fundamentals to describe the quantum point contact, which is the quantum analogue of a transistor and the basic building block of all nanoscopic circuits, such as electron interferometers. Pearsall's Quantum Photonics is supported by numerous numerical calculations that can be repeated by the reader, and every chapter features a reference list of state-of-the art research and a set of exercises. This textbook is an essential part of any graduate-level course dealing with the theory of nanophotonic devices or computational physics of solid-state quantum devices based on nanoscopic structures.