Special relativity treatment of stimulated emission

John N. Dodd

Zhenming Zhao, Mei Kong, Yameng Xu

Alan V. Durrant

The mechanisms behind the amplification of light by stimulated emission are investigated using a semiclassical approach. The theory is developed in the plane wave mode picture so as to follow closely the correspondence with the usual quantized field treatment. It is shown that the interference between stimulating and stimulated fields is an essential process for producing the well-known first-order effects, and that interference between stimulated emission fields from different atoms in the sample determines the spatial distribution of the amplification when this is measured locally using a light detector without mode discrimination.

A. F. Harvey

Murray, Iii Sargent

In this book we treat the interaction of radiation with matter with special application to gain (amplifying) media typically existing in lasers. Tradition­ ally the interaction of radiation with matter is treated in terms of the index of refraction and the absorption of light, utilizing the model of electrons on springs. In Chap. 3 we show that this model is reasonable for some linear absorbing systems but is very awkward, if not outright unworkable, for a microscopic description of gain media. The essential failure of the electron-spring model is its difficulty in yielding net stimulated emission (and therefore gain) for an ensemble of systems.t In contrast, a more physically sound, quantum treatment of matter provides for the concept of population inversion and explains stimulated emission in a natural way. Hence from the very start we are compelled to base our understanding of the interaction of radiation with matter on a quantum-mechanical description of atoms. In Chaps. 1-13 a classical field interacts with quantum-mechanical atoms; in the remainder of the book, both field and atoms are treated quantum mechani­ cally.

H.-G. Unger