Special Issue: Optoelectronics

This issue is devoted to what is variously called optoelectronics or photonics, and I have been privileged to assist PHYSICS TODAY as a guest editor in the coverage of this sparkling field. Photonics and microelectronics are the two key technologies of the rapidly growing information industry, and their advances are complementing each other in the tasks of the acquisition, transmission, storage and processing of increasing amounts of information. The principal technical elements of photonics are the photonic semiconductor devices, such as the junction laser, and the optical fibers made of fused silica. Advances in photonics are already making significant contributions to the transmission of information via optical fibers, to the high‐capacity mass storage of information in laser disks, and to the acquisition of information with the help of optical fiber sensors. The first article, by Tingye Li (on page 24), presents a review and perspective of the lightwave transmission technology via optical fibers. Yasuharu Suematsu (on page 32) presents an overview of semiconductor junction lasers, which represent a central building block of photonics; progress in this field has allowed a shift of operation to the optimal wavelengths for fiberoptics and has led to significant improvements of laser reliability and spectral purity. Aram Mooradian (on page 42) deals with the ultimate limitations to the spectral purity or coherence of lasers, which are determined by the interplay of such fundamental processes as the spontaneous and stimulated emission of radiation. The fourth and final article, by Daniel S. Chemla (on page 56), describes new vistas opened up for photonic devices by the new physics and materials science of quantum wells in semiconductors, and sketches some potential applications. Fascinating as they are, these four reviews of selected areas of progress in photonics represent only an incomplete illustration of the whole field, which is advancing on a broad front. PHYSICS TODAY hopes to cover related topics in future issues.