ABSTRACT
This chapter links the two topics of optical waveguide propagation (chapter A6) and optical resonator physics (chapter A2.1). An optical resonator can contain any sort of aperture, lens, mirror, prism and obstruction. The total resonator thus formed will have its own self-repeating field patterns. The principle that a ‘resonator mode’ is self-repeating in phase and amplitude (or that it is an eigenvector for the resonator round trip) is rather general and powerful, extending even to apparently complicated structures. The presence of a waveguide, as either a minor or a major ‘obstruction’, does not affect this principle and need not cause alarm. Waveguides are, from one popular and useful viewpoint, only ‘apertures’—albeit extended 3D ones. This chapter tries to make readers familiar with their presence and effects.
