Targeting the needs of war ...

The continuing war in Iraq and ongoing concern about terrorism elsewhere serve to underscore efforts aimed at finding technology-based solutions to many security problems. Optoelectronics has much to offer in this respect and significant resources are directed at addressing the many challenges. The ability to detect and identify biological agents is one obvious security need-ideally with instantaneous results, no false positives or negatives, low cost, and portability. Such stringent specifications, even inside a laboratory, are difficult to meet, however (see p. 85). Another security requirement-more sophisticated personnel screening tools-appears to have advanced more quickly. Newly developed compact terahertz sources may soon make terahertz screening cameras a practical reality, with the added benefit that they can also identify the spectral signatures of explosives (see p. 52). Other developments include improving remote surveillance technology (see p. 117) and detectors with extended spectral range that are able to do a job with one device that previously required two-advancing night vision and surveillance systems, as well as potentially leading to new commercial applications (see p. 109).

. . . and peace

Given today’s unremitting emphasis on safety and security, it’s easy to lose sight of the fact that photonics also has much to do with the lighter side of life (forgive the pun). Our cover picture this month brings back 30-year-old memories of climbing onto an office rooftop in the West End of London. Back then-before barcode scanners and laser pointers-the opportunity to see a “live” laser beam was relatively rare. So the prospect of seeing a blue/green beam streaking across the night sky to illuminate the face of Big Ben was not to be missed. As the cover image demonstrates, laser-based displays have evolved far from a stationary beam shining across darkened rooftops. Driven by a relatively small but passionate group of artists and technicians, and aided by a host of new technologies, state-of-the-art laser entertainment now involves a sophisticated array of photonics technologies-including scanners, spatial-light modulators, and multicolored lasers-as well as significant computing power. These changes have served to grow the market and created new opportunities for laser-based entertainment companies (see p. 73).