Our group works to develop and apply dual-comb spectroscopy (DCS) as a tool for laboratory and field measurements relevant to atmospheric science and combustion. We have develeped open-path DCS for atmospheric measurements over kilometer to multi-kilometer scale of many trace gases that are critical to climate change and air quality. We have demonstrated open-path dual-comb spectroscopy (DCS) in the near-infrared spectral region for a variety of applications including determining greenhouse gases (GHG) emissions in urban areas, oil/gas production regions, and in an agricultural setting. In addition, we have developed a new system in the mid-infrared spectral region that can measure more gases including volatile organic compounds (VOCs), which are important for understanding ozone formation. In the laboratory, we have a variety of comb systems covering the 1-12 um and have explored applications including fundamental spectroscopy, combustion, chemical reactions, and emissions from microalgae.

Currently, we have opportunities on a variety of different projects utilizing frequency combs across spectral regions for laboratory and field measurments:

• Field measurements of emissions and air quality in the Colorado Front Range as well as other urban areas 
• Field measurements of NH3 including developing improved measurements using different wavelength regions, measuring emissions at agricultural sites, and investigate impacts on air quality
• Test mitigation methods of reducing harmful gas emissions from agricultural sites
• Study laboratory and field emissions from forest fires and agricultural burning and impact on local air quality
• Measure emissions of gases from soil and sub-surface soil concentrations to better understand soil health and emissions drivers
• Extend DCS to infrared fingerprint spectral region and apply to laboratory and field measurements of VOCs, NH3/HNO3/HONO, fluorinated gases, and other gases of interest
• Develop extremely high sensitivity, multi-species measurement capability with cavity enhancement
• Explore quantum methods to improve sensitivity of DCS

References:

1. https://www.nist.gov/programs-projects/greenhouse-gas-and-atmospheric-trace-gas-measurements
2. Cossel, K. C., Waxman, E. M., Giorgetta, F. R., Cermak, M., Coddington, I. R., Hesselius, D., Ruben, S., Swann, W. C., Truong, G.-W., Rieker, G. B., and Newbury, N. R.: Open-path dual-comb spectroscopy to an airborne retroreflector, Optica, 4, 724–728, https://doi.org/10.1364/OPTICA.4.000724, 2017.
3. Cossel, K. C., Waxman, E. M., Hoenig, E., Hesselius, D., Chaote, C., Coddington, I., and Newbury, N. R.: Ground-to-UAV, laser-based emissions quantification of methane and acetylene at long standoff distances, Atmospheric Measurement Techniques, 16, 5697–5707, https://doi.org/10.5194/amt-16-5697-2023, 2023.
4. Giorgetta, F. R., Peischl, J., Herman, D. I., Ycas, G., Coddington, I., Newbury, N. R., and Cossel, K. C.: Open-Path Dual-Comb Spectroscopy for Multispecies Trace Gas Detection in the 4.5–5 $/mu$m Spectral Region, Laser & Photonics Reviews, 15, 2000583, https://doi.org/10.1002/lpor.202000583, 2021.
5. Herman, D. I., Weerasekara, C., Hutcherson, L. C., Giorgetta, F. R., Cossel, K. C., Waxman, E. M., Colacion, G. M., Newbury, N. R., Welch, S. M., DePaola, B. D., Coddington, I., Santos, E. A., and Washburn, B. R.: Precise multispecies agricultural gas flux determined using broadband open-path dual-comb spectroscopy, Sci Adv, 7, eabe9765, https://doi.org/10.1126/sciadv.abe9765, 2021.
6. Herman, D. I., Mead, G., Giorgetta, F. R., Baumann, E., Malarich, N. A., Washburn, B. R., Newbury, N. R., Coddington, I., and Cossel, K. C.: Open-path measurement of stable water isotopologues using mid-infrared dual-comb spectroscopy, Atmospheric Measurement Techniques, 16, 4053–4066, https://doi.org/10.5194/amt-16-4053-2023, 2023.
8. Malarich, N., Cossel, K., Deschenes, J.-D., Giorgetta, F., Washburn, B., Newbury, N., Genest, J., and Coddington, I.: REMOVING BIASES IN DUAL FREQUENCY COMB SPECTROSCOPY DUE TO DIGITIZER NONLINEARITY, Optics Express, doi: 10.1364/OE.497497, https://doi.org/10.1364/OE.497497, 2023a.
9. Malarich, N., Giorgetta, F. R., Mead, G., Baumann, E., Genest, J., Newbury, N. R., Coddington, I., and Cossel, K. C.: Evaluating CO2 and CH4 absorption models with open-path dual-comb spectroscopy at the mauna loa observatory, Journal of Quantitative Spectroscopy and Radiative Transfer, 345, 109567, https://doi.org/10.1016/j.jqsrt.2025.109567, 2025.
10. Malarich, N. A., Washburn, B. R., Cossel, K. C., Mead, G. J., Giorgetta, F. R., Herman, D. I., Newbury, N. R., and Coddington, I.: Validation of open-path dual-comb spectroscopy against an O2 background, Opt. Express, 31, 5042–5055, https://doi.org/10.1364/OE.480301, 2023b.
11. Mead, G. J., Waxman, E. M., Bon, D., Herman, D. I., Baumann, E., Giorgetta, F. R., Friedlein, J. T., Ycas, G., Newbury, N. R., Coddington, I., and Cossel, K. C.: Open-path dual-comb spectroscopy of methane and VOC emissions from an unconventional oil well development in Northern Colorado, Frontiers in Chemistry, 11, 1202255, 2023.
12. Mead, G. J., Herman, D. I., Giorgetta, F. R., Malarich, N. A., Baumann, E., Washburn, B. R., Newbury, N. R., Coddington, I., and Cossel, K. C.: Apportionment and Inventory Optimization of Agriculture and Energy Sector Methane Emissions Using Multi-Month Trace Gas Measurements in Northern Colorado, Geophysical Research Letters, 51, e2023GL105973, https://doi.org/10.1029/2023GL105973, 2024.
13. Waxman, E. M., Cossel, K. C., Giorgetta, F., Truong, G.-W., Swann, W. C., Coddington, I., and Newbury, N. R.: Estimating vehicle carbon dioxide emissions from Boulder, Colorado, usinghorizontal path-integrated column measurements, Atmospheric Chemistry and Physics, 19, 4177–4192, https://doi.org/10.5194/acp-19-4177-2019, 2019.
14. Ycas, G., Giorgetta, F. R., Cossel, K. C., Waxman, E. M., Baumann, E., Newbury, N. R., and Coddington, I.: Mid-infrared dual-comb spectroscopy of volatile organic compounds across long open-air paths, Optica, OPTICA, 6, 165–168, https://doi.org/10.1364/OPTICA.6.000165, 2019.
15. Ycas, G., Giorgetta, F. R., Friedlein, J. T., Herman, D., Cossel, K. C., Baumann, E., and Coddington, I.: Compact mid-infrared dual-comb spectrometer for outdoor spectroscopy, Opt. Express, OE, 28, 14740–14752, https://doi.org/10.1364/OE.385860, 2020.

Frequency comb; Nonlinear optics; Spectroscopy; Dual comb Spectroscopy; Ultrafast Optics; Agricultural gas measurements; Atmospheric chemistry; Combustion; Trace gas measurement

citizenship

Open to U.S. citizens

level

Open to Postdoctoral applicants