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Search Publications by: Chris Yung (Fed)

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Displaying 1 - 19 of 19

Extremely broadband calibrated bolometers and microbolometer arrays for Earth radiation budget measurements

September 30, 2022
Author(s)
Michelle Stephens, Chris Yung, Nathan Tomlin, Dave Harber, Cameron Straatsma, Atasi Dan, Erica Freire Antunes, Peter Pilewskie, Odele Coddington, John H. Lehman
The Earth radiation budget, a 40-year data record of the balance between solar radiation reaching the Earth and the amount absorbed, reflected, and emitted from the Earth, is a key climate record for determining whether the Earth is warming or cooling. The

High-accuracy room temperature planar absolute radiometer based on vertically aligned carbon nanotubes

July 1, 2021
Author(s)
Anna Vaskuri, Michelle Stephens, Nathan Tomlin, Matthew Spidell, Chris Yung, Andrew Walowitz, Cameron Straatsma, David Harber, John H. Lehman
We have developed a Planar Absolute Radiometer for Room Temperature (PARRoT) that will replace the legacy C-series calorimeter as the free-space continuous-wave laser power detector standard at the National Institute of Standards and Technology (NIST)

Room temperature Laser Power Standard Using a Microfabricated, Electrical Substitution Bolometer

February 18, 2021
Author(s)

Michelle Stephens, Christopher Yung, Nathan Tomlin, Anna Vaskuri, Ivan Ryger, Matthew Spidell, Malcolm G. White, Thomas Jenkins, Jennifer Landry, Tesfatsion Sereke, John Lehman

The design and performance of a room temperature electrical substitution radiometer for use as an absolute standard for measuring continuous-wave laser power over a wide range of wavelengths, beam diameters and powers is described. The standard achieves an

Transparent High-Frequency Ultrasonic Transducer for Photoacoustic Microscopy Application

September 1, 2020
Author(s)
Jeeseong Hwang, Christopher S. Yung, Ruimin Chen, Yun He, Junhui Shi, Lihong Wang, Qifa Zhou
We report the development of an optically transparent high-frequency ultrasonic transducer using lithium niobate single-crystal and indium-tin-oxide electrodes with up to 90 % optical transmission in the visible to near infrared spectrum. The center

Dual-comb photoacoustic spectroscopy

June 19, 2020
Author(s)
Jacob T. Friedlein, Esther Baumann, Kimberly Briggman, Gabriel M. Colacion, Fabrizio R. Giorgetta, Daniel I. Herman, Nathan R. Newbury, Jeeseong Hwang, Ian R. Coddington, Kevin C. Cossel, Gabriel Ycas, Christopher Yung, Eli V. Hoenig, Edgar F. Perez, Aaron Goldfain
Spectrally-resolved photoacoustic imaging is a promising technique for label-free imaging in optically scattering materials. However, this technique often requires acquisition of a separate image at each wavelength of interest. This reduces imaging speeds

Microfabricated bolometer based on a vertically aligned carbon nanotube absorber

March 2, 2020
Author(s)
Anna K. Vaskuri, Michelle S. Stephens, Nathan A. Tomlin, Christopher S. Yung, Andrew J. Walowitz, Cameron Straatsma, Dave Harber, John H. Lehman
We have designed a microfabricated planar absolute radiometer based on a vertically aligned carbon nanotube (VACNT) absorber and an electrical power substitution method. The radiometer is designed to operate at room temperature and to be capable of

Compact total irradiance monitor: Flight demonstration

August 30, 2019
Author(s)
Dave Harber, John H. Lehman, Nathan A. Tomlin, Christopher Yung, Malcolm White, Zach Castleman, Ginger Drake, Samuel Van Dreser, Nat Farber, Karl Heurman, Joel Rutkowski, Alan Sims, Jacob Sprunck, Cameron Straatsma, Isaac Wanamaker, Wengang Zheng, Greg Kopp, P. Pilewskie, Michelle Stephens
The long-term balance between Earth's absorption of solar energy and emission of radiation to space is a fundamental climate measurement. Total solar irradiance (TSI) has been measured from space, uninterrupted, for the past 40 years via a series of

BABAR: Black Array of Broadband Absolute Radiometers for far infrared sensing

May 13, 2019
Author(s)
Christopher S. Yung, Nathan A. Tomlin, Cameron Straatsma, Joel Rutkowski, Erik Richard, Dave Harber, John H. Lehman, Michelle S. Stephens
Currently at NIST, there is an effort to develop a black array of broadband absolute radiometers (BABAR) for far infrared sensing. The linear array of radiometer elements is based on uncooled vanadium oxide (VOx) microbolometer pixel technology but with

High-resolution, high-contrast mid-infrared imaging of fresh biological samples with ultraviolet-localized photoacoustic microscopy

May 13, 2019
Author(s)
Junhui Shi, Terrence Wong, Yun He, Lei Li, Ruiying Zhang, Christopher Yung, Jeeseong C. Hwang, Lihong Wang
Mid-infrared (MIR) microscopy provides rich chemical and structural information about biological samples, without staining. Conventionally, the long MIR wavelength severely limits the lateral resolution owing to optical diffraction; moreover, the strong

Cryogenic Primary Standard for Optical Fibre Power Measurement

August 17, 2018
Author(s)
Malcolm G. White, Zeus Ruiz, Christopher S. Yung, Igor Vayshenker, Nathan A. Tomlin, Michelle S. Stephens, John H. Lehman
NIST has completed commissioning a new, state-of-the-art cryogenic primary standard for optical fibre power measurement and calibration. It establishes for the first time, a direct traceability route between the device under test and primary standard. Two

Characterisation of New Planar Radiometric Detectors using Carbon Nanotube Absorbers under Development at NIST

June 13, 2018
Author(s)
Malcolm G. White, Nathan A. Tomlin, Christopher S. Yung, Michelle S. Stephens, Ivan Ryger, Solomon I. Woods, John H. Lehman, Igor Vayshenker
Carbon nanotube technology, in conjunction with silicon micro-fabrication techniques, has enabled us to develop planar radiometric detectors, which has led to the establishment of a new generation of primary standards. The goal is to develop compact, fast

Reduction of Short Wavelength Reflectance of Multi-wall Vertically Aligned Carbon Nanotubes Through UV Laser Irradiation

May 29, 2018
Author(s)
Michelle S. Stephens, Brian J. Simonds, Christopher S. Yung, Davis R. Conklin, David J. Livigni, Alberto R. Oliva, John H. Lehman
Multi-wall carbon nanotube coatings are used as broadband, low-reflectance absorbers for bolometric applications, blackbody radiators, and for stray light control. Irradiation of single wall carbon nanotubes with UV laser light has been shown to remove

Carbon Nanotube-Based Black Coatings

February 15, 2018
Author(s)
John H. Lehman, Christopher S. Yung, Nathan A. Tomlin, Davis R. Conklin, Michelle S. Stephens
It has been shown that coatings comprised of carbon nanotubes are very black; that is, characterized by low reflectance over a broad wavelength range from the visible to far infrared. Arguably there is no other material that is comparable. This is

Plasma modification of vertically aligned carbon nanotubes: superhydrophobic surfaces with ultra- low reflectance

November 2, 2017
Author(s)
Christopher S. Yung, Nathan A. Tomlin, Karl Heuerman, Mark W. Keller, Malcolm G. White, Michelle S. Stephens, John H. Lehman
Vertically aligned carbon nanotubes (VACNTs) are excellent broadband (UV–VIS–IR) absorbers of light that can be made even darker with plasma treatments. Modification of VACNTs using O2 and/or CF4 plasmas is shown to have a significant impact on the