The Loudon quantum theory of light has several key features, including:

The Quantum Theory of Light by Loudon is a comprehensive textbook on the quantum theory of light, covering topics such as:

The complete piece you're looking for is likely:

: Using time-dependent quantum mechanics to explain how light interacts with matter.

If your library does not own the ebook, request an ILL. The library will scan a physical copy and send you a personal-use PDF of the chapters you need—typically within 1 week.

For a history of how Loudon’s work shaped the field of quantum optics, you can read the recent commemorative article in Philosophical Transactions A from the Royal Society.

The historical and theoretical foundation of why light must be quantized.

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