A5053494561- Spectroscopy and Laser Applications
- Atmospheric Ozone and Climate
- Molecular Spectroscopy and Structure
- Atmospheric and Environmental Gas Dynamics
- Acoustic Wave Resonator Technologies
- Photonic and Optical Devices
- Electron Spin Resonance Studies
- Advanced Chemical Physics Studies
- Calibration and Measurement Techniques
- Photochemistry and Electron Transfer Studies
- Atmospheric aerosols and clouds
- Atomic and Molecular Physics
- Terahertz technology and applications
- Mass Spectrometry Techniques and Applications
- Spectroscopy and Quantum Chemical Studies
- Advanced MEMS and NEMS Technologies
- Porphyrin and Phthalocyanine Chemistry
- Gyrotron and Vacuum Electronics Research
- Precipitation Measurement and Analysis
- Superconducting and THz Device Technology
- Advanced Fiber Laser Technologies
- Optical and Acousto-Optic Technologies
- Advanced Semiconductor Detectors and Materials
- Soil Moisture and Remote Sensing
- Microwave and Dielectric Measurement Techniques
Jet Propulsion Laboratory
2017-2024
California Institute of Technology
2017-2019
Yale University
2013-2016
Oberlin College
2007-2013
Washington State University
2007
University of Missouri–Kansas City
2007
University of Edinburgh
2007
The accuracy of atmospheric trace gas retrievals depends directly on the molecular absorption model used within retrieval algorithm. For remote sensing well-mixed gases, such as carbon dioxide (CO2), where variability is small compared to background, quality key. Recent updates oxygen (O2) coefficients (ABSCO) for 0.76 µm A-band and water vapor (H2O) continuum 1.6 2.06 CO2 bands Orbiting Carbon Observatory (OCO-2 OCO-3) algorithm are described here. Updates in O2 involve inclusion new...
We report the infrared photodissociation spectrum of tagged protonated valine in range 1000–1900 cm–1, prepared a cryogenic ion trap. Comparison experimental results with calculated spectra based on density functional theory shows that hydroxyl group carboxylic acid functionality and amine adopt trans configuration. Nitrogen methane molecules were used as messenger tags optimal tagging temperatures 30 K for N2 60 CH4. While suggest only weak influence tag frequency positions ValH+, measured...
A complete 183-GHz CMOS/Indium Phosphide (InP) hybrid heterodyne-spectrometer is realized for spaceborne atmospheric remote sensing applications. It captures spontaneous emission from thermally populated pure rotational states investigating Earth/planetary atmosphere and interstellar media. Recent missions such as the heterodyne instrument far-infrared, microwave limb sounder, Rosetta orbiter highlighted wealth of scientific knowledge that can be attained by utilizing...
This work presents a benchtop method for collecting the room temperature gas phase infrared (IR) action spectra of protonated amino acids and their isomers. The adopted setup uses minimally modified commercial electrospray ionization linear ion trap mass spectrometer (ESI-LIT-MS) coupled to broadband continuous wave (cw) quantum cascade laser (QCL) source. approach leverages messenger assisted spectroscopic techniques using water-tagged molecular ions with complex formation, irradiation,...
Direct time-domain sampling oscilloscopic capture of ultra-high bandwidth (32-102 GHz) modulated optical waveforms at 1550 nm is demonstrated power levels below -100 dBm. To detect fast directly far what traditional oscilloscope methods can measure, we use a time-correlated single-photon counting (TCSPC) acquisition method, recently developed integrated electro-optic devices with >100 GHz bandwidth, and single photon detectors <; 5 ps jitter. We show the reconstruction time domain signals by...
A broadband, high efficiency polarized beam splitter (PBS) metagrating based on integrated resonant units (IRUs) to enable simultaneous polarization analysis, spectral dispersion, and spatial imaging in the near infrared (NIR) is developed. PBS with a diameter of 60 mm key technology component high-resolution multiple-species atmospheric profiler NIR (HiMAP-NIR), which spaceborne instrument concept crafted be core payload NASA's new generation Earth System Observatory. HiMAP-NIR will aerosol...
IR and Raman spectra are reported for 1,1-difluorocyclopropane-d0, -d2, -d4, complete assignments of vibrational fundamentals given these species. These consistent with predictions frequencies, intensities, depolarization ratios computed the B3LYP/cc-pVTZ quantum chemical (QC) model. Ground state rotational constants five 13C deuterium isotopomers, obtained from published microwave spectra, were "corrected" into equilibrium constants. The needed vibration-rotation interaction QC models after...
Infrared spectra obtained in gas and liquid argon phases are reported for (12)CF(2) horizontal line(12)CH(2) line(13)CH(2). These firmly establish the positions of nu(3)(A(1)) nu(6)(A(2)) both isotopomers. Using anharmonicity constants from MP2 calculations, Fermi resonances affecting nu(1)(A(1)), nu(2)(A(1)), nu(3), nu(8)(B(1)) analyzed. Deperturbed fundamental frequencies these analyses used conjunction with unaffected fundamentals ab initio data to predict all 12 "observed" harmonic...
We report the infrared photodissociation spectrum of tagged protonated valine in range 1000 – 1900 cm-1, prepared a cryogenic ion trap. Comparison experimental results with calculated spectra based on density functional theory shows that hydroxyl group carboxylic acid functionality and amine adopt trans configuration. Nitrogen methane molecules were used as messenger tags, optimal tagging temperatures 30 K for N2 60 CH4. While suggest only weak influence tag frequency positions ValH+,...
A compact and low-power complementary metal oxide semiconductor (CMOS)-based transmitter with an operational bandwidth of 90-105 GHz has been deployed as the radiation source in a high-resolution sub-Doppler (Lamb-dip) absorption spectrometer. The output can be both frequency amplitude modulated allowing for application highly sensitive detection schemes commonly used molecular spectroscopy. CMOS shown to have sufficient power perform spectral hole burning saturation experiments phase-noise...
The performance of a CMOS transmitter designed for planetary science in situ molecular sensing applications having an operational bandwidth 180-190 GHz and peak output power 0.6 mW (-2.22 dBm) is evaluated with series spectroscopic-based experimental trials. Continuous wave frequency modulated absorption schemes are exploited to probe the Doppler sub-Doppler lineshape profiles water rotational transition at 183.310 GHz. These results demonstrate tuning finesse phase-noise characteristics...
We present a system level description of cavity-enhanced millimeter-wave spectrometer that is the first in its class to combine source and detection electronics constructed from architectures commonly deployed mobile phone industry traditional pulsed Fourier transform techniques realize compact device capable sensitive specific situ gas detections. The instrument, which has an operational bandwidth 90-102 GHz, employs several unique components, including custom-designed pair transmitter...
The origin band of the Ã1B2-X1A1 (π* ← π) absorption system in monodeuterated tropolone (TrOD) has been probed with near-rotational resolution by applying frequency-domain techniques polarization-resolved degenerate four-wave mixing (DFWM) spectroscopy under ambient, bulk-gas conditions. Judicious selection polarization geometries for incident and detected electromagnetic waves alleviated intrinsic spectral congestion facilitated dissection overlapping transitions, thereby enabling refined...
The near-ultraviolet π*←π absorption system of weakly bound complexes formed between tropolone (TrOH) and formic acid (FA) under cryogenic free-jet expansion conditions has been interrogated by exploiting a variety fluorescence-based laser-spectroscopic probes, with synergistic quantum-chemical calculations built upon diverse model chemistries being enlisted to unravel the structural dynamical properties pertinent ground [X̃1A'] excited [Ã1A'π*π] electronic states. For binary TrOH ⋅ FA...
This paper presents an overview of a sub-orbital flight demonstration with 183 GHz and 540-600 limb-sounding instrument aboard stratospheric ballooncraft. The band provides soundings H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O is implemented hybrid CMOS-InP receiver architecture which excellent sensitivity while remaining compact (162 g) offering extremely low DC power consumption (0.62 W). channel sounds...
Time-domain sampling oscilloscopic capture of ultra-high bandwidth modulated optical waveforms at 1550 nm is demonstrated ultra-low power levels below −100dBm, with eye SNR varying from 13dB 30 GHz to 6dB 100 GHz.
Abstract The exploration of icy body composition in the solar system has often involved spectroscopic measurements volatiles detected with remote sensing, such portray materials naturally expelled from surface that enter exosphere and potentially escape into space. Variations ratio deuterium hydrogen these have led to inconclusive hypotheses regarding potential cometary origins Earth’s ocean water and/or organics. Observational biases unknown previous processing observable ejected...