Instead, leverage your university library, request an ILL, or purchase the official ebook for $70–90. Consider it an investment in your quantum optics career—a book you will reference for 20+ years.
The Loudon quantum theory of light, also known as the Loudon theory or quantum optics, is a theoretical framework that describes the behavior of light in the context of quantum mechanics. The theory was developed by Rodney Loudon, a British physicist, in the 1960s. The theory posits that light is composed of photons, which are quantized particles that exhibit both wave-like and particle-like behavior. loudon quantum theory of light pdf link
For those interested in learning more about the quantum theory of light, we recommend the following resources: Instead, leverage your university library, request an ILL,