Skip to main content
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: David Long (Fed)

Search Title, Abstract, Conference, Citation, Keyword or Author
Displaying 1 - 25 of 30

Optical-cavity-based primary sound standard

February 1, 2023
Akobuije Chijioke, Richard A. Allen, Steven E. Fick, David Long, Benjamin Reschovsky, Jared Strait, Randall P. Wagner
We propose an optical sound standard in which the sound pressure is directly measured by using an optical cavity to observe the induced change in the refractive index of air. In this method, an optical cavity is coupled with an acoustic cavity, with the

Intrinsically accurate sensing with an optomechanical accelerometer

May 18, 2022
Benjamin Reschovsky, David Long, Feng Zhou, Yiliang Bao, Richard A. Allen, Jason J. Gorman, Thomas W. LeBrun
We demonstrate a microfabricated optomechanical accelerometer that is capable of percent-level accuracy without external calibration. To achieve this capability, we use a mechanical model of the device behavior that can be characterized by the thermal

Improvement of the spectroscopic parameters of the air- and self-broadened N2O and CO lines for the HITRAN2020 database applications

June 11, 2021
Robab Hashemi, Iouli Gordon, Erin Adkins, Joseph T. Hodges, Manfred Birk, David Long, Chris Boone, Adam Fleisher, Adriana Predoi-Cross, Laurence Rothman
This paper outlines the major update of the line-shape parameters that were performed for the nitrous oxide (N2O) and carbon monoxide (CO) molecules listed in the HITRAN2020 database. We reviewed the collected measurements for the air- and self-broadened

Broadband thermomechanically limited sensing with an optomechanical accelerometer

March 9, 2021
Feng Zhou, Yiliang Bao, Ramgopal Madugani, David Long, Jason J. Gorman, Thomas W. LeBrun
Cavity optomechanics has enabled precision measurements with unprecedented levels of sensitivity, including the detection of attonewton forces, nanoparticles, magnetic fields, and gravitational waves. In most cases, detection is performed in a narrow

Electro-optic frequency combs for rapid interrogation in cavity optomechanics

January 29, 2021
David Long, Benjamin J. Reschovsky, Feng Zhou, Yiliang Bao, Thomas W. LeBrun, Jason Gorman
Electro-optic frequency combs were employed to rapidly interrogate an optomechanical sensor, demonstrating spectral resolution substantially exceeding that possible with a mode-locked frequency comb. Frequency combs were generated using an integrated

Improving the Retrieval of XCO2 from Total Carbon Column Network Solar Spectra

January 3, 2019
Joseph Mendonca, Kimberly Strong, Debra Wunch, Geoffrey Toon, David Long, Joseph T. Hodges, Vincent T. Sironneau
High-resolution absorption spectra of the a^1 ∆_g←X^3 Σ_g^- O2 band measured using cavity ring-down spectroscopy were fitted using the Voigt and speed-dependent Voigt line shapes. We found that the speed-dependent Voigt line shape was better able to model

Multiheterodyne Spectroscopy Using Multi-frequency Combs

May 13, 2017
David F. Plusquellic, Gerd A. Wagner, Adam Fleisher, David Long, Joseph T. Hodges
Near-IR dual frequency combs generated from waveform driven electro-optic phase modulators (EOMs) are used for high resolution studies in low pressure cells and for remote sensing from natural targets (Boulder Flatirons). Arbitrary waveform generators

Multiplexed sub-Doppler spectroscopy with an optical frequency comb

December 13, 2016
David A. Long, Adam J. Fleisher, David F. Plusquellic, Joseph T. Hodges
An optical frequency comb generated with an electro-optic phase modulator and a chirped radiofrequency waveform is used to perform saturation spectroscopy on the D1 and D2 transitions of atomic potassium. With a comb tooth spacing of 2 MHz and a bandwidth

Coherent cavity-enhanced dual-comb spectroscopy

May 4, 2016
Adam J. Fleisher, David A. Long, Zachary D. Reed, David F. Plusquellic, Joseph T. Hodges
Multiheterodyne spectroscopy performed with two stabilized optical frequency combs (OFCs) has shown great potential as a fast, accurate, and high-resolution substitute for existing interferometry methods that require lengthy integration times and precision

Mid-infrared molecular spectroscopy in the quantum noise limit

March 31, 2016
David A. Long, Adam J. Fleisher, Qingnan Liu, Joseph T. Hodges
A cavity ring-down spectrometer was used to reach the quantum noise limit in the mid-infrared spectral region. Quantum noise was observed not only in the individual ring-down decay events but also in the corresponding ensemble statistics with a magnitude

Observations of Dicke narrowing and speed dependence in air-broadened CO2 lineshape near 2.06 um

November 3, 2014
Thinh Q. Bui, David Long, Agata Cygan, Vincent T. Sironneau, Daniel Hogan, Priyanka M. Rapusinghe, Mitchio Okumura
Frequency-stabilized cavity ring-down spectroscopy (FS-CRDS) was used to study CO2 lineshapes in the (20013)←(00001) band centered near 2.06 um. Two rovibrational transitions were chosen for this study to measure non-Voigt collisional effects for air

Multiheterodyne spectroscopy with optical frequency combs generated from a continuous-wave laser

May 1, 2014
David A. Long, Adam J. Fleisher, Kevin O. Douglass, Stephen E. Maxwell, Katarzyna E. Bielska, Joseph T. Hodges, David F. Plusquellic
Dual-drive Mach-Zehnder modulators were utilized to produce power-leveled optical frequency combs (OFCs) from a continuous-wave laser. The resulting OFCs contained up to fifty unique frequency components and spanned more than 200 GHz. Simple changes to the

Quantum-noise-limited cavity ring-down spectroscopy

March 29, 2014
David A. Long, Adam J. Fleisher, Szymon S. Wojtewicz, Joseph T. Hodges
Spectroscopic techniques with ultra-high sensitivity allow for the study of a wide variety of physical and chemical phenomena, ranging from the interrogation of individual atoms1 and molecules2,3 to the quantitative extraction of ensemble properties from

Rapid scan absorption spectroscopy using a waveform-driven electro-optic phase modulator in the 1.6- 1.65 ym region

September 25, 2013
Kevin O. Douglass, Stephen Maxwell, Gar W. Truong, Roger D. van Zee, Joseph T. Hodges, David Long, David F. Plusquellic
A method is reported for performing fast optical frequency scans over a bandwidth of 36.9 GHz and at a sweep rate of 40 kHz using a single second-order sideband from an electro-optic phase modulator driven by an arbitrary waveform generator. Single