This Advanced Study Institute on the Electronic Properties of Multilayers and Low Dimensional Semiconductor Structures focussed on several of the most active areas in modern semiconductor physics. These included resonant tunnelling and superlattice phenomena and the topics of ballistic transport, quantised conductance and anomalous magnetoresistance effects in laterally gated two-dimensional electron systems. Although the main emphasis was on fundamental physics, a series of supporting lectures described the underlying technology (Molecular Beam Epitaxy, Metallo-Organic Chemical Vapour Deposition, Electron Beam Lithography and other advanced processing technologies). Actual and potential applications of low dimensional structures in optoelectronic and high frequency devices were also discussed. The ASI took the form of a series of lectures of about fifty minutes' duration which were given by senior researchers from a wide range of countries. Most of the lectures are recorded in these Proceedings. The younger members of the Institute made the predominant contribution to the discussion sessions following each lecture and, in addition, provided most of the fifty-five papers that were presented in two lively poster sessions. The ASl emphasised the impressive way in which this research field has developed through the fruitful interaction of theory, experiment and semiconductor device technology. Many of the talks demonstrated both the effectiveness and limitations of semiclassical concepts in describing the quantum phenomena exhibited by electrons in low dimensional structures.

This volume contains the Proceedings of the NATO Advanced Research Workshop on "Optical Properties of Narrow-Gap Low-Dimensional Structures," held from July 29th to August 1st, 1986, in St. Andrews, Scotland, under the auspices of the NATO International Scientific Exchange Program. The workshop was not limited to optical properties of narrow-gap semiconductor structures (Part III). Sessions on, for example, the growth methods and characterization of III-V, II-VI, and IV-VI materials, discussed in Part II, were an integral part of the workshop. Considering the small masses of the carriers in narrow-gap low dimensional structures (LOS), in Part I the enhanced band mixing and magnetic field effects are explored in the context of the envelope function approximation. Optical nonlinearities and energy relaxation phenomena applied to the well-known systems of HgCdTe and GaAs/GaAIAs, respectively, are reviewed with comments on their extension to narrow gap LOS. The relevance of optical observations in quantum transport studies is illustrated in Part IV. A review of devices based on epitaxial narrow-gap materials defines a frame of reference for future ones based on two-dimensional narrow-gap semiconductors; in addition, an analysis of the physics of quantum well lasers provides a guide to relevant parameters for narrow-gap laser devices for the infrared (Part V). The roles and potentials of special techniques are explored in Part VI, with emphasis on hydrostatic pressure techniques, since this has a pronounced effect in small-mass, narrow-gap, non-parabolic structures."