Accurate measurement of optical radiation is important for the optical communications, medical device, semiconductor lithography, manufacturing and materials processing industries, and it also has scientific applications for solar irradiance, Earth radiance, accurate calibration of astronomical instruments, and emerging needs of quantum information. Our group performs research and development to extend the accuracy, wavelength range, power range, robustness, and portability of radiometric standards. We use advanced nanfabrication techniques coupled with carbon nanotube technologies to investigate new ways to provide SI-traceable, accurate, and robust optical power measurements to the scientific and industrial community. Our research extends from single photon detectors to kW laser powers and from the ultra-violet to THz wavelengths. We follow our technology from concept to application by creating, building, and characterizing our state-of-the-art detectors and then integrating them into packages that are, for example, included into new national standards or planned for launch into space on CubeSats. Our work has a strong international component through visiting guest researchers and intercomparisons with other National Metrology Institutes.

References:

J. Lehman, C. Yung, N. Tomlin, D. Conklin, M. Stephens, Carbon nanotube-based black coatings, Applied Physics Reviews 5, 011103 (2018).

Christopher S. Yung, Nathan A. Tomlin, Karl Heuerman, Mark W. Keller, Malcolm G. White, Michelle Stephens, John Lehman, Plasma modification of vertically aligned carbon nanotubes: Superhydrophobic surfaces with ultra-low reflectance, Carbon 127, 195 (2018).

Ivan Ryger, Dave Harber, Michelle Stephens, Malcolm White, Nathan Tomlin, Matthew Spidell, John Lehman, Noise characteristics of thermistors: Measurement methods and results of selected device, Rev. Sci. Instr. 88, 024707 (2017).

John Lehman, Andreas Steiger, Nathan Tomlin, Malcolm White, Mathias Kehrt, Ivan Ryger, Michelle Stephens, Christian Monte, Ingmar Mueller, Joerg Hollandt, Marla Dowell, Planar hyperblack absolute radiometer, Optics Express 24 (23) 25911 (2016).

Nathan Tomlin, John Lehman, Carbon nanotube electrical-substitution cryogenic radiometer: initial results, Optics Lett. 38, 175 (2013).