U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Search Publications

NIST Authors in Bold

Displaying 776 - 800 of 853

Effect of Line Width Roughness on Optical Scatterometry Measurements

April 6, 2009
Author(s)
Brent C. Bergner, Thomas Germer, Thomas Suleski
Line width roughness (LWR) has been identified as a potential source of uncertainty in scatterometry measurements, and characterizing its effect is required to improve the method s accuracy and to make measurements traceable. In this work, we extend

EUVL dosimetry at NIST

March 13, 2009
Author(s)
Charles S. Tarrio, Steven E. Grantham, Marc J. Cangemi, Robert E. Vest, Thomas B. Lucatorto, Noreen Harned
As part of its role in providing radiometric standards in support of industry, NIST has been active in advancing extreme ultraviolet dosimetry on various fronts. Recently, we undertook a major effort in accurately measuring the sensitivity of three extreme

Scatterfield Optical Imaging for sub-10 nm Dimensional Metrology

January 1, 2009
Author(s)
Richard M. Silver
Recent developments in optical microscopy promise to advance optical metrology and imaging to unprecedented levels through theoretical and experimental development of a new measurement technique called "scatterfield optical imaging". ". Current metrology

Computational Parameters in Simulation of Microscope Images

November 28, 2008
Author(s)
Egon Marx, James E. Potzick
The simulation of microscope images computed from scattered fields determined using integral equations depend on a number of parameters that are not related to the scatterer or to the microscope but are choices made for the computation method. The effect

Integral Equations for 3-D Scattering: Finite Strip on a Substrate

November 28, 2008
Author(s)
Egon Marx
Singular integral equations that determine the exact fields scattered by a dielectric or conducting finite strip on a substrate are presented. The computation of the image of such a scatterer from these fields by Fourier optics methods is also shown.

Yb Optical Lattice Clock

November 23, 2008
Author(s)
Nathan D. Lemke, Andrew Ludlow, Zeb Barber, N Poli, C.W. Hoyt, Long-Sheng Ma, Jason Stalnaker, Christopher W. Oates, Leo Hollberg, James C. Bergquist, A. Brusch, Tara Fortier, Scott Diddams, Thomas P. Heavner, Steven R. Jefferts, Tom Parker
We describe the development and latest results of an optical lattice clock based on neutral Yb atoms, including investigations based on both even and odd isotopes. We report a fractional frequency uncertainty below 10 -15 for 171Yb.

Calibration of a Radiance Standard for the NPP/OMPS Instrument

October 9, 2008
Author(s)
Bettye C. Johnson, James J. Butler, Scott J. Janz, Robert D. Saunders, John W. Cooper, Matthew G. Kowalewski, R Barnes
In June 2007, a spherical integrating source was calibrated in the National Aeronautics and Space Administration(NASA) Goddard Space Flight Center’s (GSFC) Calibration Facility as part of the prelaunch characterization program for the NPOESS Preparatory

Measuring Optical Tunneling Times using a Hong-Ou-Mandel Interferometer.

September 23, 2008
Author(s)
Sergey Polyakov, Alan L. Migdall, Paul D. Lett, David Papoular, Pierre Clade, Colin McCormick
We report a prediction for the delay measured in an optical tunneling experiment using Hong-Ou-Mandel (HOM) interference, taking into account the Goos-Hanchen shift generalized to frustrated total internal reflection situations. We precisely state

Detector-based calibration procedures for tristimulus colorimeter standards

September 15, 2008
Author(s)
George P. Eppeldauer, Carl C. Miller, Yoshihiro Ohno
Two reference and three working standard tristimulus colorimeters have been developed at the National Institute of Standards and Technology (NIST) to utilize the recently introduced detector based colorimeter calibration method [1]. The tristimulus

Angle-dependent infrared reflectance measurements in support of VIIRS

August 14, 2008
Author(s)
Simon G. Kaplan, Leonard M. Hanssen, Enrique J. Iglesias
We have developed a goniometric reflectometer using a Fourier-transform infrared (FTIR) spectrometer source for polarized reflectance measurements from 1 um to 20 um wavelength at angles of incidence from 10° to 80°, with an incident beam geometry of

High-stability transfer of an optical frequency over long fiber-optic links

August 1, 2008
Author(s)
Paul A. Williams, William C. Swann, Nathan R. Newbury
We present theoretical predictions and experimental measurements for the achievable phase noise, timing jitter, and frequency stability in the coherent transport of an optical frequency over a fiber-optic link. Both technical and fundamental limitations to

Applications of highly coherent femtosecond fiber lasers

July 13, 2008
Author(s)
Nathan R. Newbury, Ian R. Coddington, William C. Swann
Coherent, broadband fiber lasers produce pulse trains with <1 femtosecond relative timing uncertainty and <1 mHz relative frequency uncertainty. These sources can advance many applications including optical frequency metrology, ranging LIDAR, and broadband

Improving squeezing purity from a KNbO 3 crystal by temperature tuning

May 4, 2008
Author(s)
Thomas Gerrits, Tracy S. Clement, Scott Glancy, Richard P. Mirin, Sae Woo Nam, Emanuel Knill
We show a method to increase the purity of a squeezed state generated by a femtosecond laser and down-conversion crystal. The method relies on temperature tuning the down- and up-converting crystals, which changes the spatial and spectral output mode of

Practical performance limits on optical frequency transfer over fiber optic links

May 4, 2008
Author(s)
Paul A. Williams, William C. Swann, Nathan R. Newbury
We present theory and experiment quantifying the limitations to stable transport of optical frequencies over optical fiber. These are fundamental fiber noise, propagation delay, bidirectional propagation and system noise in the measurement interferometers.

Fast-responding nonlinear phase shifter using a signal-wave gain medium

April 22, 2008
Author(s)
Lu Deng, Edward W. Hagley, Kaijun Jiang, Marvin G. Payne
Using a full density matrix formalism we show that for a lifetime broadened four-level scheme with a signal wave gain medium a large nonlinear phase shift can be induced without signal wave slowdown and attenuation. In this system the signal wave acquires

Direct Experimental Observation of the Goos Hanchen Shift

April 9, 2008
Author(s)
H G. Schwefel, W Kohler, Z Lu, Jingyun Fan, L Wang
We report a precise direct measurement of the Goos-Hanchen (GH) shift after one reflection off a dielectric interface coated with periodic metal stripes. The spacial displacement of the shift is determined by image analysis. A maximal absolute shift of 5

Uniform and enhanced field emission from chromium oxide coated carbon nanosheets

April 2, 2008
Author(s)
Uwe Arp, Kun Hou, Ronald Outlaw, Wang Sigen, Mingyao Zhu, Ronald Quinlan, Dennis Manos, Martin Kordesch, Brian Holloway
Carbon nanosheets, a two-dimensional carbon nanostructure, are promising electron cathode materials for applications in vacuum microelectronic devices. This letter demonstrates a simple approach to improve the spatial emission uniformity of carbon
Displaying 776 - 800 of 853
Was this page helpful?