Sandia National Laboratories researchers Hope Michelsen and Jeff Tsao have been elected fellows of The Optical Society. Michelsen was elected for pioneering contributions to the fundamental understanding of laser-radiation interactions with soot particles through laser-induced incandescence, absorption, scattering and laser-induced incandescence to assess environmental impacts of carbonaceous particle. “It is an opportunity for me to remember and express gratitude for all of the great people I’ve worked with in developing the optical diagnostics for soot and black carbon that have brought me this honor,” Michelsen said. “I have also been very fortunate to have stable funding through the Department of Energy’s Basic Energy Sciences program to accomplish this work. Michelsen’s research program focuses on developing and using optical techniques for studying the chemistry of combustion-generated particles inside the combustor and their impact on climate when released to the atmosphere. Her research experience includes gas-surface scattering experiments, atmospheric modeling, soot-formation studies, combustion-diagnostics development, atmospheric black-carbon measurements and greenhouse-gas source attribution. Tsao was elected for seminal, sustained contributions over 20 years to solid-state lighting and its materials and optoelectronic device foundations. His career path includes two national laboratories and brief stints in industry and academia. In the late 1990s, when the efficiency of phosphor-converted white light LEDs was only a few percent, few researchers thought these glowing white rocks might someday be used for general illumination. However, Tsao and colleagues at Sandia and HP co-authored a paper that predicted efficiencies as high as 50 percent and the enormous energy-savings potential that would be realized if achieved. The white paper is widely credited with inspiring solid-state lighting activity all over the world. He later served on Energy Department committees that outlines possible paths for improved LED lighting and came up with new ways of improving LED efficiencies and usefulness. His published solid-state lighting work has accumulated 1,750 citations. Tsao said the fellow award “is also recognition of the many wonderful colleagues at Sandia and elsewhere with whom I have been fortunate to have worked, and of Sandia as an institution, whose exceptional service in the national interest inspires the kind of forward-looking research in the national interest that the award was for.” The Optical Society is the leading professional association in optics and photonics.