Quantum optics and fundamentals of quantum theory

Jan Peřina, Z. Hradil, Branislav Jurčo

Aleksei M. Zheltikov

Abstract The Keldysh photoionization theory is a conceptual cornerstone and a universal framework for the description of a broad class of fundamental effects in light–matter interaction. Here, we provide an overview of the Keldysh theory as a significant milestone in the development of modern optical physics and offer a historical perspective on the fundamental role of this theory, from the early pioneering work on quantum tunneling to the latest breakthroughs in laser optics, attosecond technologies, and ultrafast optics of high-intensity laser pulses.

P. Lambropoulos, David Petrosyan

A. V. Gitin

All known quantum-mechanical approaches to wave and statistical optics are united into a single theory, using Feynman's path integral as a fundamental principle. In short-wave approximations, this principle, the Fourier transformations, and concepts of the theory reproduce Fermat's principle, the Legendre transformations, and concepts of Hamilton's optics and radiometry in a one-to-one fashion.

Frank Vollmer, Deshui Yu

Toshiaki Suhara

This chapter provides the basis for the discussion in the following chapters by summarizing the fundamental concepts and the quantum theory concerning the interaction between electrons and photons in a form that is convenient for theoretical analysis of semiconductor lasers [1-9]. First, quantization of electromagnetic fields of optical waves is outlined, and the concept of a photon is clarified. Quantum theory expressions for coherent states are also given. Then the quantum theory of electronphoton interactions and the general characteristics of optical transitions are explained. Fundamental mathematical expressions for absorption, spontaneous emission, and stimulated emission of photons are deduced, and the possibility of optical wave amplification in population-inverted states is shown.