ELECTROMAGNETIC POWER PROVIDED BY SOURCES WITHIN MULTILAYER OPTICS - FREE-SPACE AND MODAL PATTERNS

An electromagnetic theory is presented that makes possible the develop ment of a complete energy balance within an arbitrary multilayer micro cavity that supports different kinds of classical optical sources. The theory is based on a single Fourier spectrum of waves and is valid fo r transparent or dissipative stacks, with no use of modal methods. We show how the power provided by the cavity is converted into Poynting f lux and absorption. Free-space and guided-mode patterns are calculated for single layers, mirrors, and narrow-band filters. The modal patter n is shown to be strongly dependent on the cavity poles. Discretizatio n of the high-frequency energy into a set of guided modes is introduce d as an asymptotic limit of the problem when absorption vanishes to ze ro. The applications concern defect-induced absorption in optical mult ilayers or guided-mode coupling through microirregularities in a stack , as well as spontaneous emission in classical microcavities. (C) 1997 Optical Society of America.