Digital cameras rely on silicon to turn light into electrical current. But for folks who want to work outside the visible spectrum, digital cameras haven't served so well.

North Carolina State University physics professor Jan Schetzina, with Honeywell researchers, has replaced the silicon with the semiconductor gallium nitride to build a camera that is sensitive to ultraviolet but not to visible light. Because flames glow brightly in the UV, the military could use such a camera to track missile launches. Industry could apply it to monitor welding processes. The Defense Advanced Research Projects Agency, which helped fund Schetzina's research, has given $1.4 million to Nitres in Westlake Village, Calif., to develop a UV camera.