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Search Publications by: John H. Lehman (Fed)

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Displaying 1 - 25 of 154

Enhancement of Optical Absorption by Oxygen Plasma Treatment in Carbon Nanotube-based Black Paint Coating

July 5, 2023
Author(s)
Atasi Dan, Joel Rutkowski, Patrick McArdle, Erica Freire Antunes, Nathan Tomlin, Malcolm White, Michelle Stephens, John H. Lehman
Effect of oxygen (O2) plasma treatment on reflectance properties and surface morphology of CNT-based paint was investigated. We demonstrate a specular reflectance less than 0.10% and hemispherical reflectance less than 2.5% throughout the UV-Vis-NIR range.

Single Photon Detectors and Metrology

October 26, 2022
Author(s)
Sonia Buckley, Michelle Stephens, John H. Lehman
For quantum applications, it is important to generate quantum states of light and detect them with extremely high efficiency. For future applications, it also important to do this at scale. This presents many engineering and metrology challenges. This

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

Generalized Electrical Substitution Methods and Detectors for Absolute Optical Power Measurements

June 17, 2022
Author(s)
Solomon I. Woods, Jorge Neira, James E. Proctor, Joseph P. Rice, Nathan Tomlin, Malcolm White, Michelle Stephens, John H. Lehman
We have developed generalized methods for electrical substitution optical measurements, as well as cryogenic detectors which can be used to implement them. The new methods enable measurement of arbitrary periodic waveforms by an electrical substitution

Absolute radiation pressure detector using a diamagnetically levitating test mass

October 28, 2021
Author(s)
Anna Vaskuri, Daniel Rahn, Paul A. Williams, John H. Lehman
We have developed an absolute radiometer to measure laser power by means of radiation pressure in a closed control-loop configuration using diamagnetically levitated pyrolytic graphite as the soft spring and gravity as a contactless restoring force. Our

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

Simplified kilogram traceability for photon momentum radiometers

October 1, 2020
Author(s)
Kyle A. Rogers, Paul A. Williams, Gordon A. Shaw, John H. Lehman
High power laser applications in areas such as laser processing of materials can require an accurately measured laser power. Radiation pressure-based laser power measurement has been proven as a practical method for quantifying these high-power levels in

Calibration of free-space and fiber-coupled single-photon detectors

September 14, 2020
Author(s)
Thomas Gerrits, Alan L. Migdall, Joshua C. Bienfang, John H. Lehman, Sae Woo Nam, Oliver T. Slattery, Jolene D. Splett, Igor Vayshenker, Chih-Ming Wang
We present our measurements of the detection efficiency of free-space and fiber-coupled single- photon detectors at wavelengths near 851 nm and 1533.6 nm. We investigate the spatial uniformity of one free-space-coupled silicon single-photon avalanche diode

Radiation Pressure Laser Power Meter for Industrial Laser Machining

September 10, 2020
Author(s)
Aly Artusio-Glimpse, Ivan Ryger, Natalia A. Azarova, Paul A. Williams, John H. Lehman
Demonstration and validation of a linear radiation pressure-based high-power laser power meter is presented. To date, this device is the most promising real-time, absolute power meter for laser material processing where power monitoring is crucial.

HALO - High Amplification Laser-pressure Optic

June 21, 2020
Author(s)
Alexandra B. Artusio-Glimpse, Kyle A. Rogers, Paul A. Williams, John H. Lehman
Efforts are underway at the National Institute of Standards and Technology to drastically reduce the uncertainty of laser power measurements using radiation pressure. The High Amplification Laser-pressure Optic (HALO) system is a cornerstone of this effort

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

Calibration of free-space and fiber-coupled single-photon detectors

December 20, 2019
Author(s)
Thomas Gerrits, Alan L. Migdall, Joshua C. Bienfang, John H. Lehman, Sae Woo Nam, Jolene D. Splett, Igor Vayshenker, Chih-Ming Wang
We measure the detection efficiency of single-photon detectors at wavelengths near 851 nm and 1533.6 nm. We investigate the spatial uniformity of one free-space-coupled single-photon avalanche diode and present a comparison between fusion-spliced and

Optical-Fiber Power Meter Comparison between NIST and LAMETRO

November 1, 2019
Author(s)
Johnny Jimenez, Maria Ugalde, John H. Lehman, Igor Vayshenker
We describe the results of a comparison of reference standards between the National Institute of Standards and Technology (NIST-USA) and Laboratorio de Metrologia, Instituto Costarricense de Electricidad (LAMETRO-ICE, COSTA RICA) for optical fiber-based

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

Inline Laser Power Measurement by Photon Momentum

February 6, 2019
Author(s)
John H. Lehman, Paul A. Williams, Daniel W. Rahn, Kyle A. Rogers
We present a measurement scheme and instrumentation for quantifying laser power by means of photon momentum. The optical design is optimized such that the incoming laser beam is minimally perturbed and is available for other purposes along the incoming

Radiation-Pressure Enabled Traceable Laser Sources at High CW Powers

January 4, 2019
Author(s)
Paul A. Williams, Alexandra B. Artusio-Glimpse, Joshua A. Hadler, Daniel King, Ivan Ryger, Tam Vo, John H. Lehman, Kyle A. Rogers
Radiation pressure has recently been shown to have practical application for multi-kilowatt CW laser power measurement. One key advantage lies in its ability to measure without absorbing the laser beam. This enables a new measurement paradigm where laser

Time-Resolved Absorptance and Melt Pool Dynamics during Intense Laser Irradiation of a Metal

October 25, 2018
Author(s)
Brian J. Simonds, Jeffrey W. Sowards, Joshua A. Hadler, Erik A. Pfeif, Boris Wilthan, Jack R. Tanner, Paul A. Williams, John H. Lehman
Laser welding is a complex, dynamic process by which focused, high-intensity laser light is used to join two metallic surfaces and is being increasing deployed in a variety of industrial applications. Determining the time-dependent absorptance of the laser

Using Radiation Pressure to Develop a Radio-Frequency Power Measurement Technique Traceable to the Redefined SI

October 15, 2018
Author(s)
Christopher L. Holloway, Matthew T. Simons, David R. Novotny, John H. Lehman, Paul A. Williams, Gordon A. Shaw
We discuss a power measurement technique traceable to the International System of Units based on radiation pressure (or radiation force) carried by an electromagnetic wave. A measurement of radiation pressure offers the possibility for a power measurement