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Search Publications by: David Long (Fed)

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Displaying 1 - 25 of 33

Low-power, agile electro-optic frequency comb spectrometer for integrated sensors

March 11, 2024
Author(s)
Kyunghun Han, David Long, Sean Bresler, Junyeob Song, Yiliang Bao, Benjamin Reschovsky, Kartik Srinivasan, Jason J. Gorman, Vladimir Aksyuk, Thomas W. LeBrun
Sensing platforms based upon photonic integrated circuits have shown considerable promise; however, they require corresponding advancements in integrated optical readout technologies. Here, we present an on-chip spectrometer that leverages an integrated

Nanosecond time-resolved dual-comb absorption spectroscopy

October 30, 2023
Author(s)
David Long, Matthew Cich, Carl Mathurin, Garrett Mathews, Adam Heiniger, Augustine Frymire, Gregory Rieker
Frequency combs have revolutionized the field of optical spectroscopy, enabling researchers to probe molecular systems with a multitude of accurate and precise optical frequencies. Although there have been tremendous strides in direct frequency comb

Single-modulator, direct frequency comb spectroscopy via serrodyne modulation

February 3, 2023
Author(s)
David Long, Sean Bresler, Yiliang Bao, Benjamin Reschovsky, Thomas W. LeBrun, Jason J. Gorman
Traditional electro-optic frequency comb spectrometers rely upon the use of an acousto-optic modulator (AOM) to provide a differential frequency shift between probe and local oscillator (LO) legs of the interferometer. Here we show that these modulators

Optical-cavity-based primary sound standard

February 1, 2023
Author(s)
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
Author(s)
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
Author(s)
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
Author(s)
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
Author(s)
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
Author(s)
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
Author(s)
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
Author(s)
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
Author(s)
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
Author(s)
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
Author(s)
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
Author(s)
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