Bridging the reality gap

The advent of new technologies is usually exciting and frequently can fire up the imagination to the point of “irrational exuberance.” The upshot is that too often there’s a significant gap between a novel concept and its practical reality. As with many other areas of high tech, the history of photonics is littered with the unmet expectations and unfulfilled promises produced by this “reality gap,” which may exist for any number of reasons (such as markets and economics) besides the technology itself.

In his “Photonics Frontiers” article this month, contributing editor Jeff Hecht highlights the potential for this gap in the context of photonic crystals. Because they can confine light using internal microstructures, photonic crystals offer tremendous promise. The development challenge, he says, is in realizing that promise in practical devices (see p. 79). While holey fibers are probably the most well-known embodiment of the technology, others are emerging. For example, novel photonic-crystal substrates for surface-enhanced Raman spectroscopy were on show at Photonics West in January and can significantly improve the reproducibility of the Raman technique (see p. 38). There were plenty of other advances to see at Photonics West, by the way, and we’ll be covering many of the highlights this month and next, starting with an overview of the event on p. 13.

Diode-pumped solid-state (DPSS) lasers are another example of a technology for which the initial expectations moved ahead of reality, as a number of problems (including diode output, cost, and reliability) quickly moderated their growth. But annual sales of DPSS lasers are now approaching $300 million, and significant progress has been made with development of high-power diode lasers for pumping of both DPSS and fiber lasers (see p. 59).

Incidentally, the history of photonics also includes the idea (circa 1965) of using lasers commercially for felling trees (see p. 50). Now there’s a reality gap!