Quantum Optics for Engineers

Appendix B: Brief Survey of Laser Resonators and Laser Cavities

B.1  Introduction

A laser is composed of a gain medium, a mechanism to excite that medium, and an optical resonator and/or optical cavity (Duarte, 2003). The terms optical cavity, optical oscillator, and optical resonator are approximately equivalent, but usage of these terms indicates that an optical cavity applies equally to an optical oscillator or an optical resonator. The term optical resonator tends to be associated with unstable resonators, while optical oscillator tends to be identified with narrow-linewidth oscillators. In this regard, narrow-linewidth multiple-prism grating oscillators can behave as unstable resonators depending on the lensing properties of the gain ...