Textbook in PDF format Authored by a highly regarded researcher and pioneer in the field, Quantum Entanglement and Interferometry offers a complete revision to the subject, including basic theory and concepts, with continued emphasis on experimental aspects. The author provides a thorough overview on basic methods of classical and quantum measurements in optical science, paints a picture of light in terms of Einstein's quantized electromagnetic wavepacket and the quantum mechanical concept of photon. In addition, readers will become familiarized with quantum superposition, including the superpositions of one-photon state, two-photon state, and multi-photon state, which saliently capture the essential physics of all optical observations