Publications

Displaying 26 - 40 of 40

Low noise thermistor read out for wideband room temperature infrared detectors

September 25, 2016

Author(s)

Ivan Ryger, Michelle S. Stephens, John H. Lehman, Matthew T. Spidell, Malcolm G. White, Nathan A. Tomlin, Dave Harber, Peter Lobotka

An absolute electrical substitution radiometer is a way to ensure highly accurate and stable measurement of optical power in a wide range of optical wavelengths. Its sensitivity is mainly determined by the temperature stability of the equithermal bath and

Terahertz laser power measurement comparison

September 5, 2016

Author(s)

John H. Lehman, Malcolm G. White, Andreas Steiger, Ralf Mueller, Alberto R. Oliva, Yuqiang Deng, Qing Sun

Abstract: A comparison of terahertz (THz) laser power measurements was undertaken among three national metrology institutes. At two THz frequencies, 2.52 THz (119 µm) and 0.762 THz (394 µm), a power level of approximately 3 mW was compared at one place at

Planar electrical-substitution carbon nanotube cryogenic radiometer

March 30, 2015

Author(s)

Nathan A. Tomlin, Malcolm G. White, Igor Vayshenker, Solomon I. Woods, John H. Lehman

A detector combining quantum and thermal primary radiometric standards in the same artefact

November 20, 2014

Author(s)

Malcolm G. White, Nathan A. Tomlin, Jarle Gran

We present the concept of a dual mode cryogenic detector, utilising a predictable quantum efficient silicon photodiode, and demonstrate the behaviour of the detector from room temperature down to 30K. The detector absorbs visible radiation generating

A CW calibrated laser pulse energy meter for the range 1 pJ to 100mJ

May 13, 2014

Author(s)

Malcolm G. White, Rodney W. Leonhardt, David J. Livigni, John H. Lehman

We describe the use of a silicon photodiode trap detector and digital storage oscilloscope as an absolute laser pulse energy meter, capable of repetition rates of 85 Hz and 5% uncertainty (k = 2). The maximum repetition rate is limited by the decay time of

Decrease in reflectance of vertically-aligned carbon nanotubes after oxygen plasma treatment

March 30, 2014

Author(s)

Nathan A. Tomlin, Alexandra Curtin, John H. Lehman, Malcolm G. White

Oxygen plasma treatment was used to lower the reflectance of multiwall vertically-aligned carbon nanotubes (VACNT). Specular reflectance measurements at an incident angle of 65° from normal show a decrease in reflectance over the wavelength range of 250

Optical constants and spatial uniformity of thermally grown oxide layer of custom, induced-junction, silicon photodiodes for a predictable quantum efficient detector

June 28, 2013

Author(s)

Malcolm G. White

We have investigated the optical properties of self-induced inversion-layer silicon photodiodes using spectroscopic ellipsometric measurement techniques. We report a self-consistent data set and dispersion relation for the optical constants of the

Realisation of an accurate and repeatable wavelength scale for double subtractive monochromators

October 30, 2012

Author(s)

Malcolm G. White

We present the results and discussion of two methods for achieving a higher degree of wavelength accuracy of double grating monochromators. In particular, we assessed the benefits of using differential evolution curve fitting techniques to minimize

Search Publications by: Malcolm White (Assoc)