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Search Publications by: Thomas Purdy (Assoc)

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Displaying 1 - 12 of 12


August 1, 2019
Zeeshan Ahmed, Nikolai N. Klimov, Thomas P. Purdy, Tobias K. Herman, Kevin O. Douglass, Ryan P. Fitzgerald
For the past century, industrial temperature measurements have relied on resistance measurement of a thin metal wire or thin metal film whose resistance varies with temperature. Today’s resistance thermometers can routinely measure temperatures with

Quantum-based vacuum metrology at NIST

June 20, 2018
Julia K. Scherschligt, James A. Fedchak, Zeeshan Ahmed, Daniel S. Barker, Kevin O. Douglass, Stephen P. Eckel, Edward T. Hanson, Jay H. Hendricks, Thomas P. Purdy, Jacob E. Ricker, Robinjeet Singh
The measurement science in realizing and disseminating the SI unit for pressure, the pascal (Pa), has been the subject of much interest at NIST. Modern optical-based techniques for pascal metrology have been investigated, including multi-photon ionization

Towards Replacing Resistance Thermometry with Photonic Thermometry

December 6, 2017
Nikolai Klimov, Thomas P. Purdy, Zeeshan Ahmed
Resistance thermometry provides a time-tested method for taking temperature measurements that has been painstakingly developed over the last century. However, fundamental limits to resistance-based approaches along with a desire to reduce the cost of

Optomechanical Quantum Correlations at Room Temperature

June 23, 2017
Thomas P. Purdy, Karen E. Grutter, Kartik A. Srinivasan, Jacob M. Taylor
By shining laser light through a nanomechanical beam, we measure the beam’s thermally driven vibrations and perturb its motion with optical forces at a level dictated by the Heisenberg measurement-disturbance uncertainty relation. Such quantum effects are

Optomechanical Quantum Correlations

May 18, 2017
Thomas P. Purdy, Karen E. Grutter, Kartik A. Srinivasan, Nikolai N. Klimov, Zeeshan Ahmed, Jacob M. Taylor
We present methods to measure optical quantum correlations arising from an optomechanical interaction even when large classical noise sources are present. We demonstrate quantum- backaction-noise-calibrated Brownian motion thermometry as a metrological

Chip-Packaged Silicon Photonic Nanoscale Thermometers

November 30, 2016
Nikolai Klimov, Thomas P. Purdy, Zeeshan Ahmed
We report on the development of on-chip integrated packaged nanoscale silicon photonic themperature sensors capable to detect temperature difference as small as 70 µK, thus showing the potential to replace legacy-based resistance thermometers

Thermometry with Optomechanical Cavities

June 6, 2016
Thomas P. Purdy, Karen E. Grutter, Kartik Srinivasan, Nikolai Klimov, Zeeshan Ahmed, Jacob Taylor
Thermally-driven motion of a nanomechanical resonator may be employed as an absolute thermometer. We experimentally measure radiation pressure shot noise induced quantum correlations to absolutely calibrate the motional signal transduced onto an optical

Optomechanical Raman-Ratio Thermometry

September 9, 2015
Katarina Cicak, Thomas P. Purdy, Pen Li Yu, Nir Kampel, Bob Peterson, Raymond Simmonds, Cindy Regal
The temperature dependence of the asymmetry between Stokes and anti-Stokes Raman scattering can be exploited for self-calibrating, optically-based thermometry. In the context of cavity optomechanics, we observe the cavity-enhanced scattering of light

On-Chip Integrated Silicon Photonic Thermometers

September 1, 2015
Nikolai N. Klimov, Thomas P. Purdy, Zeeshan Ahmed
The fundamental limitations of resistance-based thermometry and the desire to reduce sensor ownership have produced considerable interest in the development of photonics-based temperature sensors as an alternative to resistance thermometers. Photonic