"An impossible task!" is how senior editor John Wallace characterized the challenge of sorting through a year's worth of photonics invention and innovation to find some of the highlights for our Annual Technology Review article. The scope of photonics activity seems to be ever-widening, currently ranging from the experimental realization of an electromagnetic black hole to more practical applications like the subretinal array implant to aid the vision-impaired that's featured on our cover. But—as John notes in his article—the sheer volume of photonics advances is also growing, "... from a river of innovation to a torrent." His picks from this torrent for the 2010 review range far and wide-and they make for excellent reading (see page 48).
The quest for the green-output laser diode has made noticeable progress this year. At Photonics West last January, Soraa (as Kaai then; Santa Barbara, CA) announced a 532 nm device and has subsequently pushed it to about 60 mW continuous-wave output—a factor-of-ten improvement. There are also several other groups pursuing similar goals. As contributing editor Jeff Hecht puts it, "It's the kind of horse race that's both exciting to watch and good for the field" (see page 65).
According to some estimates, the solar market as a whole practically doubled this year as compared to 2009. Continued growth will depend substantially on getting costs down as the market for photovoltaic (PV) systems becomes increasingly competitive. High production yields are a critical element of cost reduction, and among the broad range of technologies involved in making solar cells, efficient in-line inspection systems are crucial. A novel photoluminescence-based imaging system can rapidly characterize silicon samples and is on the verge of being adopted for inline monitoring during PV manufacturing (see page 35). The system is also notable because it won an award for innovation this year.