Difference frequency generation laser based spectrometers

Richter, Dirk; Fried, Alan; Weibring, Petter

doi:10.1002/lpor.200810048

Cited by 53 publications

(31 citation statements)

References 38 publications

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“…TOPSE observations by a similar absorption spectrometer using a tunable lead-salt diode laser averaged 95 pptv below 0.2 km and 60 pptv at 6-8 km . A different laser source, based on tunable difference frequency generation (DFG), was employed in ARCTAS (Weibring et al, 2007;Richter et al, 2009). Model values decrease from 50 pptv near the surface to 30 pptv in the upper troposphere.…”

Section: Median Distributionsmentioning

confidence: 99%

Chemistry of hydrogen oxide radicals (HO<sub>x</sub>) in the Arctic troposphere in spring

et al. 2010

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Abstract. We use observations from the April 2008 NASA ARCTAS aircraft campaign to the North American Arctic, interpreted with a global 3-D chemical transport model (GEOS-Chem), to better understand the sources and cycling of hydrogen oxide radicals (HO x ≡H+OH+peroxy radicals) and their reservoirs (HO y ≡HO x +peroxides) in the springtime Arctic atmosphere. We find that a standard gas-phase chemical mechanism overestimates the observed HO 2 and H 2 O 2 concentrations. Computation of HO x and HO y gasphase chemical budgets on the basis of the aircraft observations also indicates a large missing sink for both. We hyCorrespondence to: J. Mao (mao@fas.harvard.edu) pothesize that this could reflect HO 2 uptake by aerosols, favored by low temperatures and relatively high aerosol loadings, through a mechanism that does not produce H 2 O 2 . We implemented such an uptake of HO 2 by aerosol in the model using a standard reactive uptake coefficient parameterization with γ (HO 2 ) values ranging from 0.02 at 275 K to 0.5 at 220 K. This successfully reproduces the concentrations and vertical distributions of the different HO x species and HO y reservoirs. HO 2 uptake by aerosol is then a major HO x and HO y sink, decreasing mean OH and HO 2 concentrations in the Arctic troposphere by 32% and 31% respectively. Better rate and product data for HO 2 uptake by aerosol are needed to understand this role of aerosols in limiting the oxidizing power of the Arctic atmosphere.

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Section: Median Distributionsmentioning

confidence: 99%

Chemistry of hydrogen oxide radicals (HO<sub>x</sub>) in the Arctic troposphere in spring

et al. 2010

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“…Here, we are interested in generating MIR frequency combs that can be used for fully coherent dual-comb spectroscopy since this method can provide both phase and magnitude spectra of a gas at high-precision and accuracy [7,8]. Following established difference frequency generation (DFG) approaches [3,4,[10][11][12][13], we generate MIR frequency combs through DFG in a periodically poled lithium niobate (PPLN) crystal between a cw 1064 nm fiberlaser source and two coherent Er-fiber-laser frequency combs at 1.5 µm. We then investigate different interferometric configurations to measure phase and magnitude spectra of purely Doppler-broadened ro-vibrational absorption lines of the C-H stretch in methane (CH 4 ).…”

Section: Introductionmentioning

confidence: 99%

Spectroscopy with a coherent dual frequency comb interferometer at 3.4 μm

et al. 2010

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A coherent dual fiber-comb spectrometer centered at 1.5 µm wavelengths is transferred to 3.4 µm by differencefrequency generation with a 1064 nm cw laser. It is shown that the residual linewidth between the comb teeth at 3.4 µm is resolution-limited to 200 mHz; such narrow linewidths can enable coherent dual-comb spectroscopy at high-precision and signal-to-noise ratio. We then discuss different interferometric configurations for coherent dual-comb spectroscopy. We find that a two-branch interferometric setup is appropriate to measure both the magnitude and phase spectrum of purely Doppler-broadened absorption lines. An initial measurement of methane lines in the υ 3 band P-branch with a resolution of 114 MHz is demonstrated.

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“…Efficient nonlinear generation of mid-IR and THz radiation with excellent spectral properties, performed since the 1980s of the XXth century, opened the way to metrological research in these spectral regions [16,17]. However, the optical power available for experiments and the complexity of such setups were not suitable for compact and practical applications.…”

Section: Introductionmentioning

confidence: 99%

QCL-based frequency metrology from the mid-infrared to the THz range: a review

et al. 2018

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Quantum cascade lasers (QCLs) are becoming a key tool for plenty of applications, from the mid-infrared (mid-IR) to the THz range. Progress in related areas, such as the development of ultra-low-loss crystalline microresonators, optical frequency standards, and optical fiber networks for time and frequency dissemination, is paving the way for unprecedented applications in many fields. For most demanding applications, a thorough control of QCLs emission must be achieved. In the last few years, QCLs' unique spectral features have been unveiled, while multifrequency QCLs have been demonstrated. Ultra-narrow frequency linewidths are necessary for metrological applications, ranging from cold molecules interaction and ultra-high sensitivity spectroscopy to infrared/THz metrology. A review of the present status of research in this field is presented, with a view of perspectives and future applications.

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Difference frequency generation laser based spectrometers

Cited by 53 publications

References 38 publications

Chemistry of hydrogen oxide radicals (HO<sub>x</sub>) in the Arctic troposphere in spring

Chemistry of hydrogen oxide radicals (HO<sub>x</sub>) in the Arctic troposphere in spring

Spectroscopy with a coherent dual frequency comb interferometer at 3.4 μm

QCL-based frequency metrology from the mid-infrared to the THz range: a review

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Difference frequency generation laser based spectrometers

Cited by 53 publications

References 38 publications

Chemistry of hydrogen oxide radicals (HO&lt;sub&gt;x&lt;/sub&gt;) in the Arctic troposphere in spring

Chemistry of hydrogen oxide radicals (HO&lt;sub&gt;x&lt;/sub&gt;) in the Arctic troposphere in spring

Spectroscopy with a coherent dual frequency comb interferometer at 3.4 μm

QCL-based frequency metrology from the mid-infrared to the THz range: a review

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Chemistry of hydrogen oxide radicals (HO<sub>x</sub>) in the Arctic troposphere in spring

Chemistry of hydrogen oxide radicals (HO<sub>x</sub>) in the Arctic troposphere in spring