Dr. David A. Long is a research chemist in the Material Measurement Laboratory at the National Institute of Standards and Technology (NIST) in Gaithersburg, MD. His research applies cutting-edge spectroscopic techniques to present problems in optical metrology, instrumental development, and atmospheric science. He is actively working on optical frequency comb development and applications in direct frequency comb spectroscopy as well as the development of ultrasensitive, frequency-agile spectroscopic approaches. Other areas of interest include molecular and atomic spectroscopy, cavity optomechanics, and remote sensing.