While many seek a PDF for portability, there are several reasons why a physical copy or a high-quality licensed digital version is superior:
Use Python libraries like QuTiP to simulate the Fock states and Coherent states described in Loudon’s early chapters. loudon quantum theory of light pdf better
This is a "desk book." Because the notation is so standard, you will find yourself flipping back to his definitions of the correlation function for years. How to Supplement Your Reading While many seek a PDF for portability, there