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 by: John R. Lawall (Fed)

Search Title, Abstract, Conference, Citation, Keyword or Author
Displaying 1 - 25 of 99

Ultrahigh reflectivity photonic crystal membranes with optimal geometry

July 30, 2024
Author(s)
Feng Zhou, Yiliang Bao, Jason Gorman, John R. Lawall
Photonic crystal (PhC) structures with subwavelength periods are widely used for diffractive optics, including high reflectivity membranes with nanoscale thickness. Here, we report on a design procedure for 2D PhC silicon nitride membrane mirrors providing

Optomechanical feedback cooling of a 5 mm long torsional mode

November 30, 2023
Author(s)
Dianqiang Su, Yuan Jiang, Pablo Solano, Luis Orozco, John R. Lawall, Yanting Zhao
We report three orders of magnitude optical cooling of the fundamental torsional mode of a 5 mm-long, 550 nm diameter optical nanofiber. The rotation of the nanofiber couples to the polarization of guided laser fields. We use a weak laser probe to monitor

Coupling an epitaxial quantum dot to a fiber-based external-mirror microcavity

June 3, 2021
Author(s)
Andreas Muller, Edward B. Flagg, Michael Metcalfe, John R. Lawall, Glenn S. Solomon
We report the coupling of individual InAs quantum dots (QDs) to a single mode of an external-mirror optical microcavity. The external mirror is bonded to a fiber and positioned above a semiconductor sample consisting of a QD-containing GaAs layer grown

Heterodyne measurement of resonant elastic scattering from epitaxial quantum dots

June 3, 2021
Author(s)
Michael Metcalfe, Glenn S. Solomon, John Lawall
Resonant elastic scattering from InAs quantum dots (QDs) is studied by heterodyne spectroscopy. We show theoretically that heterodyne spectroscopy of a two-level quantum emitter is not sensitive to the inelastic fluorescence component. In practice, we

Tunable quantum beat of single photons enabled by nonlinear nanophotonics

November 22, 2019
Author(s)
Qing Li, Anshuman Singh, Xiyuan Lu, John Lawall, Varun Verma, Richard Mirin, Sae Woo Nam, Kartik Srinivasan
Integrated photonics is a promising approach for scalable implementation of diverse quantum resources at the chip-scale. Here, we demonstrate the integration of two essential building blocks for quantum information science - quantum sources and frequency

Quantum Frequency Conversion of a Quantum Dot Single-Photon Source on a Nanophotonic Chip

May 20, 2019
Author(s)
Anshuman Singh, Qing Li, Shunfa Liu, Ying Yu, Xiyuan Lu, Christian Schneider, Sven Hofling, John Lawall, Varun Verma, Richard Mirin, Sae Woo Nam, Jin Liu, Kartik Srinivasan
Single self-assembled InAs/GaAs quantum dots are promising bright sources of indistinguishable photons for quantum information science. However, their distribution in emission wavelength, due to inhomogeneous broadening inherent to their growth, has

Single self-assembled InAs/GaAs quantum dots in photonic nanostructures: the role of nanofabrication

June 13, 2018
Author(s)
Jin Liu, Kumarasiri Konthasinghe, Marcelo I. Davanco, John Lawall, Vikas Anant, Varun Verma, Richard Mirin, Jin Dong Song, Ben Ma, Ze Sheng Chen, Hai Qiao Ni, Zhi Chuan Niu, Kartik Srinivasan
Single self-assembled InAs/GaAs quantum dots are a promising solid-state quantum technology, with vacuum Rabi splitting, single-photon-level nonlinearities, and bright, pure, and indistinguishable single-photon generation having been demonstrated. In such

Coupled Bilayer Photonic Crystal Slab Electro-Optic Spatial Light Modulators

March 1, 2017
Author(s)
Yichen Shuai, Deyin Zhao, Corey A. Stambaugh, John R. Lawall, Weidong Zhou, Yonghao Liu
We demonstrate here a surface-normal ultracompact Fano resonance electrooptic spatial light modulator employing a stacked photonic crystal membrane capacitor-like structure. Vertically coupled optical resonance near 1.5 μm was observed, and both blue and

Observation of optomechanical buckling phase transitions

March 1, 2017
Author(s)
Jacob M. Taylor, John R. Lawall, Haitan Xu, Utku Kemiktarak, Jingyun Fan, Stephen Ragole
Correlated phases of matter provide long-term stability for systems as diverse as solids, magnets, and potential exotic quantum materials. Mechanical systems, such as relays and buckling transition spring switches can yield similar stability by exploiting

An Optomechanical Accelerometer with a High-Finesse Hemispherical Optical Cavity

February 22, 2016
Author(s)
Yiliang Bao, Felipe Guzman, Arvind Balijepalli, John Lawall, Jacob Taylor, Thomas W. LeBrun, Jason J. Gorman
A new design for an optomechanical accelerometer is presented. The design includes a hemispherical optical cavity that can achieve high finesse and a proof mass that is well-constrained by silicon nitride beams. Based on previous work and analysis, the

MEMS optomechanical accelerometry standards

July 8, 2015
Author(s)
Felipe Guzman, Yiliang Bao, Jason J. Gorman, John R. Lawall, Jacob M. Taylor, Thomas W. LeBrun
Current acceleration primary standards reach relative uncertainties of the order of 0.001 and consist of complex test facilities, typically operated at National Metrology Institutes. Our research focuses on the development of silicon mechanical oscillator

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