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Search Publications by: Joseph T. Hodges (Fed)

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Displaying 101 - 125 of 214

Direct measurements of mass-specific optical cross sections of single component aerosol mixtures

July 22, 2013
Author(s)
James Radney, Xiaofei Ma, Keith A. Gillis, Michael R. Zachariah, Joseph T. Hodges, Christopher D. Zangmeister
The optical properties of atmospheric aerosols vary widely, being dependent upon particle composition, morphology and mixing state. This diversity and complexity of aerosols motivates measurement techniques that can discriminate and quantify a variety of

Differential cavity ring-down spectroscopy

May 9, 2013
Author(s)
Jeremie B. Courtois, Katarzyna E. Bielska, Joseph T. Hodges
We present a technique called differential cavity ring-down spectroscopy (D-CRDS) for reducing etaloning effects in a ring-down spectrometer. The method relies on alternately measuring and then subtracting intra-cavity losses associated with pairwise TEM00

Frequency-agile, rapid scanning spectroscopy

April 28, 2013
Author(s)
Gar W. Truong, Kevin O. Douglass, Stephen E. Maxwell, Roger D. van Zee, David F. Plusquellic, Joseph T. Hodges, David A. Long
Challenging applications in trace gas analyses require high precision and acquisition rates.1-4 Many continuous-wave laser spectroscopy techniques exhibit significant sensitivity and potential;5 however, their scanning rates are slow because they rely upon

Coupled-cavity ring-down spectroscopy technique

August 6, 2012
Author(s)
Jeremie B. Courtois, Joseph T. Hodges
We present a technique called coupled-cavity ring-down spectroscopy (CC-RDS) for controlling the finesse of an optical resonator. Applications include extending the sensitivity and dynamic range of a cavity-enhanced spectrometer, as well as widening the

Frequency-stabilized cavity ring-down spectroscopy

March 21, 2012
Author(s)
David A. Long, A. Cygan, Roger D. van Zee, Mitchio Okumura, C. E. Miller, D Lisak, Joseph T. Hodges
This Frontiers article describes frequency-stabilized cavity ring-down spectroscopy (FS-CRDS), an ultraprecise refinement of conventional cw-CRDS. We review the technique and highlight some recent studies which have utilized FS-CRDS to perform precision

Spectroscopic Measurement of the Vapour Pressure of Ice

January 1, 2012
Author(s)
Katarzyna E. Bielska, Daniel K. Havey, Gregory E. Scace, D Lisak, Joseph T. Hodges
We present a laser absorption technique to measure the vapor pressure of ice. This method is referenced to the triple point state of water and uses frequency-stabilized cavity ring-down spec- troscopy to probe four rotation-vibration transitions of H16 2 O

Construction of a High Power OPO Laser system for Differential Absorption LIDAR

September 13, 2011
Author(s)
Kevin O. Douglass, Stephen E. Maxwell, David F. Plusquellic, Joseph T. Hodges, Roger D. van Zee, Daniel V. Samarov, James R. Whetstone
Our goal is to develop and characterize optical measurement technology to enable accurate quantification of greenhouse-gas emissions to meet the needs of industry and regulators. A 1064 nm pumped high energy optical parametric oscillator (OPO) operating

PDH-locked, frequency-stabilized cavity ring-down spectrometer

June 16, 2011
Author(s)
Joseph T. Hodges, A. Cygan, Piotr Maslowski, Katarzyna E. Bielska, S. Wojtewicz, J. Domyslawska, Hisashi Abe, R.S. Trawinski, R. Ciurylo
We describe a high sensitivity and high spectral resolution laser absorption spectrometer based upon the frequency-stabilized cavity ring-down spectroscopy (FS-CRDS) technique. We used the Pound-Drever-Hall (PDH) method to lock the probe laser to the high