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Search Publications by: John R. Lawall (Fed)

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Displaying 26 - 50 of 99

Alignment and testing of the NIST Calculable Capacitor

August 24, 2014
Author(s)
Yicheng Wang, Felipe Guzman, Corey A. Stambaugh, Radek Smid, Hugo Zuniga Calvo, Andrew D. Koffman, Jon R. Pratt, John R. Lawall
This paper reports progress on the NIST effort to develop a new calculable capacitor, focusing on improvement of the guard electrode motion control as well as issues associated with the overall electrode alignment. Design of a multi-wavelength Fabry-Perot

Mode competition and anomalous cooling in a multimode phonon laser

July 15, 2014
Author(s)
Utku Kemiktarak, Michael Metcalfe, Mathieu Durand, John R. Lawall
We study mode competition in a multimode “phonon laser” comprised of a Fabry-Perot cavity employing a highly reflective membrane as the output coupler. Mechanical gain is provided by driving the cavity with a blue-detuned pump laser, and many mechanical

Cavity optomechanics with sub-wavelength grating mirrors

December 18, 2012
Author(s)
Utku Kemiktarak, Mathieu Durand, Michael Metcalfe, John R. Lawall
We design, fabricate, and study a novel platform for cavity optomechanics: a silicon nitride membrane patterned as a sub-wavelength diffraction grating. Using the grating as one mirror of a Fabry-Perot cavity, we realize an optical finesse of $F=2830\pm 60

Accurate Gouy phase measurement in an astigmatic optical cavity

September 14, 2012
Author(s)
John R. Lawall, Mathieu Durand, Yicheng Wang
We present measurements of the Gouy phase accumulation for the fundamental mode of an astigmatic Fabry-Perot cavity over 70 % of its stability range. The method is based on simultaneous measurement of the resonant frequencies of the fundamental mode and

Mechanically Compliant Grating Reflectors for Optomechanics

February 10, 2012
Author(s)
Utku Kemiktarak, Michael Metcalfe, Mathieu Durand, John R. Lawall
We demonstrate micromechanical reflectors with a reflectivity as large as 99.4% and a mechanical quality factor Q as large as 7.8 x 10^5 for optomechanical applications. The reflectors are silicon nitride membranes patterned with sub-wavelength grating

Porous Superhydrophobic Membranes: Hydrodynamic Anomaly in Oscillating Flows

October 17, 2011
Author(s)
Sukumar Rajauria, O. Ozsun, John R. Lawall, V. Yakhot, Kamil L. Ekinci
Inspiration for man-made superhydrophobic surfaces comes from Nature: the Lotus leaf [1–3], for instance, exploits superhydrophobicity to keep its surface dry and clean from contaminants. Superhydrophobicity emerges due to roughness on a chemically

High-accuracy Fabry-Perot displacement interferometry using fiber lasers

August 8, 2011
Author(s)
Mathieu Durand, John R. Lawall, Yicheng Wang
We describe ongoing work in a Fabry-Perot interferometry system designed to measure displacements over a range of 50~mm with sub-pm uncertainty. The apparatus involves probing two nearby modes of the Fabry-Perot cavity with narrow-linewidth fiber telecom

Resolved sideband emission from dynamically strained quantum dots

July 16, 2010
Author(s)
Michael Metcalfe, Stephen M. Carr, Andreas Muller, Glenn S. Solomon, John R. Lawall
The dynamic response of InAs/GaAs self-assembled quantum dots (QDs) to strain is studied by periodically modulating the QDs with a surface acoustic wave (SAW) and measuring the QD fluorescence with both photoluminescence and resonant spectroscopy. When the

Ultrahigh finesse low mode volume Fabry-Perot microcavity

July 1, 2010
Author(s)
Andreas Muller, Edward B. Flagg, John R. Lawall, Glenn S. Solomon
Ultralow loss concave micromirrors with radii of curvature below 60 um were fabricated by laser ablation and reflective coatings. A 10 um long microcavity with a mode volume of 40 um^3 was set up with two such mirrors and the cavity linewidth measured both

Vibration spectrum of a low-vibration pulse-tube cryostat from 1 Hz to 20 kHz

January 11, 2010
Author(s)
Akobuije D. Chijioke, John R. Lawall
The vibrations of the cold finger of a low-vibration helium pulse-tube cryostat are measured from 1 Hz to 20 kHz using an optical interferometer specially designed to measure small vibrations at high frequencies in the presence of large vibrations at lower

Fabry-Perot Metrology for Displacements up to 50 mm

October 16, 2008
Author(s)
John R. Lawall
A system designed to apply Fabry-Perot interferometry to the measurement of displacements is described. Two adjacent modes of a Fabry-Perot cavity are probed, and both the absolute optical frequencies and their difference are used to determine