One of the dreams of holographers, probably dating all the way back to the invention of holography by Dennis Gabor in 1948, has been to create "free-standing" three-dimensional (3-D) images that could be viewed under normal lighting conditions and that would appear to be real objects. At last month`s North American International Auto Show in Detroit, MI, Ford Motor Co. came as close as anyone so far to realizing this dream when it unveiled a full-color display hologram of one of its concept cars. The hologram allowed visitors to view the concept vehicle in 3-D, to walk around it, and to look inside it. Ford underwrote the project as part of an ongoing assessment of optoelectronic technologies and their potential in facilitating the design of its future products. This month`s cover shows a photograph of the hologram together with a picture of the three scientists responsible for producing it, and the article on p. 14 describes how the 3-D image was created.
Semiconductor lasers dominate market
By the end of 1999 diode lasers will account for almost 60% of the total worldwide laser market revenues, and this growth shows no sign of abating. The explosive increase in the telecommunications and laser-pointer markets, together with rising sales of optical data storage devices are the primary drivers. And increased device efficiency, combined with an overabundance of certain device types (causing a drop in average pricing), serves only to fuel further growth of diode-laser-based applications. Hence, the outlook for diode-laser makers is upbeat--see Part II of the Annual review and forecast of laser markets on p. 52.
Meanwhile the use of lasers in the fabrication of semiconductor and microelectronic devices is well established and represents one of the largest markets for all lasers. Specific applications range from quality control, such as inspection and measurement with confocal microscopy, to several of the various stages in the production process--photolithography, for example, patterns integrated circuit features onto the wafers, while via drilling allows clean microscopic holes to be created in microcircuits such as multichip modules. The falling size and rising complexity of all these devices, with the concomitant increased investment required to produce them, is driving demand for more-sophisticated methods of tracking the devices through the entire fabrication process and out to the end-user. Laser-based marking has become the standard means of tracking wafers and is the subject of senior editor John Wallace`s article on p. 75, the first of this year`s series on microelectronics processing.