The Quantum Theory of Light

R. Loudon

Abstract The study of the classical theory of optical fluctuations and coherence is an important preliminary to the development of the corresponding quantum-mechanical theory. The classical theory is useful for a physical understanding of the various effects and many of the classical concepts carry over into the quantum theory. In addition, a knowledge of the classical theory is useful for identification of the nature of the specifically quantum properties that some light beams may exhibit. Thus it is shown in Chapter 5 that the classical and quantum theories yield the ame predictions for chaotic light, but that there exist other kinds of light that elude any satisfactory classical description. The nature of such ‘nonclassical’ light i5, of course, more sharply appreciated by contrast with the limitations on the possible kinds of light inherent in the classical theory.

Marc-Oliver Pleinert

Partha Pratim Mondal

Light fluctuation is strongly associated with its state. A good example of this is coherent light, for which the associated probability distribution is Poisson. This strongly suggests that the description of light and the associated fluctuations can also be understood using a distribution function. This necessitates that light be described purely on the basis of a distribution function, popularly known as the “representation theory” of light. This theory treats light as an entity that exhibit fluctuations with rich statistical significance, which justifies the description of light in the realm of quantum statistics and the development of a quasi-classical distribution theory. This is essentially an extension of the quantum theory that incorporates radiation fields with a non-standard distribution function. An equivalent and powerful approach to understanding light makes use of the Fourier domain, which is associated with the characteristic function. In this chapter, we set out to explore radiation fields, including thermal, random, and squeezed light, based on the representation theory.

Xiang-Yao Wu, Hong Li, Zhang, Bo-Jun +8 more

In this paper, we study the light double-slit diffraction experiment with quantum theory approach. Firstly, we calculate the light wave function in slits by quantum theory of photon. Secondly, we calculate the diffraction wave function with Kirchhoff's law. Thirdly, we give the diffraction intensity of light double-slit diffraction, which is proportional to the square of diffraction wave function. Finally, we compare calculation result of quantum theory and classical electromagnetic theory with the experimental data. We find the quantum calculate result is accordance with the experiment data, and the classical calculation result with certain deviation. So, the quantum theory is more accurately approach for studying light diffraction.

David W. Ball