Optical communications aside . . .

Even outside the somewhat esoteric pages of optoelectronics magazines it seems almost impossible to turn around nowadays without bumping into some aspect of the optical communications bandwagon. And while this may represent reality in the sense that telecommunications technologies such as wavelength-division multiplexing are having an almost incredible effect on our everyday lives, it is occasionally refreshing to look elsewhere for new developments in the optoelectronics field.

During the 1800s, investigation into the refraction and dispersion of light by German optician and physicist Joseph von Frauenhofer ultimately led to the invention of the spectroscope and the birth of the science of spectroscopy, an optical technique fundamental to our understanding of material composition and structure. More recently, the advent of better optics, high-quality optical fiber, and new types of detectors, among other advances, has brought about a new generation of spectroscopic instrumentation and allowed these instruments to move out of the laboratory and into the field. This month's cover picture highlights one such portable spectrometer that allows researchers to work in a variety of environments (see p. 77).

On other fronts, advances in imaging and detectors have resulted in image intensifiers that address applications beyond just the needs of the military for which they were originally developed (see p. 135), and continuing refinement of charge-coupled devices (CCDs) is aimed at keeping them competitive with potential alternatives, such as detectors based on CMOS technology (see p. 107). The use of lasers for materials processing also continues to evolve as new laser technology—like shorter wavelengths—becomes more commercially viable; hence micromachining with ultraviolet solid-state lasers allows improved resolution and cleaner cuts (see p. 115). Meanwhile new approaches to semiconductor-laser design and fabrication have produced quantum-cascade devices capable of emitting at longer infrared wavelengths that are important to spectroscopists (see p. 141).

Of course, reality being what it is, the sheer size of the market for optoelectronic devices used in optical communications (see p. 84) makes it impossible to ignore advances in these areas and inevitably leads one to speculate as to their longer-term effect in noncommunications markets. Vertical-cavity lasers, for example, are now being developed as a key technology for optical networking but are likely to have a significant long-term impact on the entire semiconductor laser market (see p. 123).