Most of the texts available on lasers deal with laser engineering and laser applications, only a few of them treating theoretical aspects of the laser at an advanced level. Introduction to Laser Physics provides an introduction to the essential physics of quantum electronics and lasers. Fundamental topics in modern optics, the applicability of various theoretical approaches, and the physical meaning of laser-related phenomena are carefully described. Experimental results and properties of practical lasers are interwoven, thereby allowing an explicit demonstration of the rate equation approach and the semiclassical treatment. The basic concepts of nonlinear optical devices and laser spectroscopy are intro- duced. The second edition includes additional information on optical resonators, minor improvements of the text and several new problems, completed with solutions.