Recent developments and applications in electroabsorption semiconductor modulators

State of the art developments in electroabsorption modulators that utilize quantum well-semiconductors are reviewed. Special emphasis is given to rece nt progress made in materials for modulators. On technological grounds, opt imized Multiple Quantum Well modulators in the GaAs/AlGaAs system have been driven by applications in photonic switching and optical interconnects. Su rprisingly, these same structures exhibit a wealth of new behavior that ran ges from Bloch oscillations to excitons in Coupled Well, Wannier-Stark and Shallow Well superlattices. Several types of excitonic phases have been ide ntified, optically and found to transform as the system dimensionality chan ges from 2D to 3D. In addition, new material systems have shown that quantu m well excitonic absorption quality can be transferred to technologically i mportant wavelengths at 1.06 or 1.55 mu m. (C) 1999 Elsevier Science S.A. A ll rights reserved.