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Search Publications by: Ulf Griesmann (Fed)

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Displaying 1 - 25 of 123

Manufacture of Extremely Flat 300 mm Silicon Wafers

October 12, 2021
Author(s)
Marc Tricard, Paul Dumas, Christopher Hall, Ulf Griesmann, Quandou (. Wang
The flatness requirement for silicon wafers at the exposure site will be lower than 50 nm by 2010 and may be as low as 25nm by 2015 (TRS 2005). This creates new challenges for both wafer polishing and metrology tools capable of meeting the specifications

Modal Reconstruction of Aspheric Surfaces From Experimental Second Derivatives

October 12, 2021
Author(s)
Nadia Machkour-Deshayes, Byoung C. Kim, Robert S. Polvani, Ulf Griesmann
A method for the measurement of precise aspheric optical surfaces based on measurements of the second derivatives of the surface is evaluated. A compact phase-measuring interferometer is used to determine the second derivatives of a surface on a survey

Binary pseudorandom array test standard optimized for characterization of large field-of-view optical interferometers

August 24, 2020
Author(s)
Valeriy V. Yashchuk, Sergey Babin, Stefano Cabrini, Weilun Chao, Ulf Griesmann, Ian Lacey, Stefano Marchesini, Keiko Munechika, Carlos Pina-Hernandez, Allen L. Roginsky
Recently, a technique for calibrating the modulation transfer function (MTF) of a broad variety of metrology instrumentation has been demonstrated. This technique is based on test samples structured as one-dimensional binary pseudo-random (BPR) sequences

A Toolbox for Isophase-Curvature Guided Computation of Metrology Holograms

August 13, 2020
Author(s)
Ulf Griesmann, Johannes A. Soons, Gufran S. Khan
We describe the algorithmic foundations of an open-source numerical toolbox, written in the Octave language, for the creation of computer-generated binary and multi-level holograms used in interferometric form error measurements of complex aspheric and

Sensing Fabrication Errors in Diffraction Gratings using High Dynamic Range Imaging

July 19, 2019
Author(s)
Sofia C. Corzo Garcia, Johannes A. Soons, Ulf Griesmann
We describe the design of a simple instrument for the identification and characterization of fabrication errors in diffraction gratings. The instrument uses an uncooled charge-coupled device (CCD) camera and a high dynamic range imaging process to detect

Process improvements in the production of silicon immersion gratings

June 26, 2016
Author(s)
Cynthia Brooks, Benjamin Kidder, Michelle Grigas, Daniel Jaffe, Ulf Griesmann, Daniel Wilson, Richard Muller
We have explored a number of lithographic techniques and improvements to produce the resist lines that then define the grating groove edges of silicon immersion gratings. In addition to our lithographic process using contact printing with photomasks, which

Wide-Field InfraRed Survey Telescope (WFIRST) Slitless Spectrometer: Design, Prototype, and Results

June 26, 2016
Author(s)
Qian Gong, David Content, Margaret Z. Dominguez, Thomas Emmett, Ulf Griesmann, Jeffrey Kruk, Catherine Marx, Bert Pasquale, Thomas Wallace
The slitless spectrometer plays an important role in the WFIRST mission for the survey of emission-line galaxies. This will be an unprecedented very wide field, HST quality 3D survey of emission line galaxies1. The concept of the compound grism as a

Interferometric measurement of large sphere radii using holograms

July 8, 2015
Author(s)
Ulf Griesmann, Quandou (. Wang, Johannes A. Soons, Kate Medicus
We describe a new interferometric method for the measurement of large sphere radii in which the converging test beam is replaced by a pair of test beams with different focal lengths. The test beams are created by a pair of holograms that are fabricated on