Thermal imaging cameras are highly useful tools for military and law enforcement types, letting them see humans inside buildings or land a helicopter in the fog. High definition models are too heavy for servicemen to tote, however, so DARPA and a private partner have built a 1,280 x 720 LIWR (long-wave infrared) imager with pixels a mere five microns in diameter. That's smaller than infrared light's wavelength, allowing a slighter device without giving up any resolution or sensitivity while costing much less, to boot. Researchers say that three functional prototypes have performed
