(published in 2000) is the definitive choice as it contains over 50% new material compared to its predecessor royalsocietypublishing.org Why the 3rd Edition is "Better"
The search for a usually stems from a student or researcher realizing that introductory physics texts don't quite bridge the gap between basic electromagnetism and true quantum optics. Rodney Loudon’s The Quantum Theory of Light is the gold standard for this transition. loudon quantum theory of light pdf better