Surface waves in integrated-optics elements with distributed coupling (review)

Abstract

A review is given of the literature on the interaction and conversion of surface waves in integrated-optics elements with distributed coupling. A general description is given of the distributed coupling of surface waves in thin-film waveguides and a detailed investigation is made of their interaction and conversion in waveguides with periodically modulated parameters. The different types of periodic modulation of the parameters of thin-film waveguides are discussed and compared. The main elements and devices in integrated-optics systems based on periodic diffraction-grating structures are examined. The possibility of using aperiodic grating structures in integrated optics is demonstrated and devices with tunnel distributed coupling are considered. PACS numbers: 42.82. + η Many phenomena in physics and engineering can be considered to be coupled wave effects. 1 In integrated optics many surface-wave distributed-coupling effects are also observed in elements and devices designed for different purposes. These include radiation scattering by irregularities in dielectric thin-film waveguides (TFW's), diffraction-induced conversion of surface waves at grating structures and directional power coupling, mode conversion, and nonlinear interactions. The devices and elements of greatest interest in integrated optics are those based on surface wave coupling and interaction effects in TFW's with periodically modulated parameters. These are used in the development of active devices such as distributed-feedback and distributed-Bragg-reflector lasers, various passive devices such as filters, radiation coupling elements, mode converters, diffraction modulators and deflectors, and are also used for spatially selective radiation filtering in TFW's. Many of these devices may find extensive applications in optical communication lines based on fiber waveguides. The present review gives a general description of the distributed coupling of surface waves in a TFW and a detailed analysis is made of the interaction and conversion of surface waves in waveguides with periodically modulated parameters. The main elements and devices in integrated-optics systems based on periodic grating structures are considered. The possibility of using aperiodic grating structures in integrated optics is demonstrated and devices with tunnel distributed coupling are examined.