Trace detection of NO_2 by frequency-modulation-enhanced magnetic rotation spectroscopy

Smith, Jason M.; Bloch, Jonathan C.; Field, Robert W.; Steinfeld, J. I.

doi:10.1364/josab.12.000964

Cited by 30 publications

(11 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…FRS has been used for many years as a very sensitive and selective technique for the spectroscopic investigation of paramagnetic molecules such as nitric oxide (Litfi n et al ., 1980 ;Adams et al ., 1984 ;Ganser et al ., 2003 ;Fritsch et al ., 2008 ;Sabana et al , 2009 ;Lewicki et al ., 2009 ;Kluczynski et al ., 2011 ), nitrogen dioxide (Dillenschneider and Curl, 1983 ;Smith et al , 1995 ), oxygen (Brecha et al ., 1997 ;So et al ., 2011 ) and hydroxyl radicals (Pfeiffer et al ., 1981 ;Zhao et al , 2011 ). This technique takes advantage of the dispersion effects of paramagnetic molecules immersed in a longitudinal magnetic fi eld to reveal their unique property to rotate light polarization.…”

Section: Faraday Rotation Spectroscopy (Frs)mentioning

confidence: 99%

Tunable mid-infrared laser absorption spectroscopy

Tittel

Lewicki

2013

Semiconductor Lasers

View full text Add to dashboard Cite

Section: Faraday Rotation Spectroscopy (Frs)mentioning

confidence: 99%

Tunable mid-infrared laser absorption spectroscopy

Tittel

Lewicki

2013

Semiconductor Lasers

View full text Add to dashboard Cite

“…Which method is best depends on many factors: laser power, source noise in the laser, saturation of the absorption, and detector parameters (sensitivity, saturation, linearity, etc.). Additional frequency modulation can be used with any of the FRS methods to approach quantum noise (QN)-limited performance (8). In this work, we have used the simple single-detector approach with nearly crossed polarizers.…”

Section: Frsmentioning

confidence: 99%

“…When the 2 approaches were compared on the NO fundamental (9), FRS sensitivity was found to be an order of magnitude better than the LMRS technique. FRS has been used as an extremely sensitive technique for the detection of paramagnetic molecules such as NO (1,7,(10)(11)(12), nitrogen dioxide (8,13), oxygen (14), or hydroxyl radicals (15). FRS is well suited for atmospheric measurements of free radicals (16) or for exhaled breath analysis because interference from diamagnetic species (such as water and carbon dioxide) is eliminated.…”

Section: Frsmentioning

confidence: 99%

Ultrasensitive detection of nitric oxide at 5.33 μm by using external cavity quantum cascade laser-based Faraday rotation spectroscopy

Lewicki

Doty

Curl

et al. 2009

Proc. Natl. Acad. Sci. U.S.A.

137

109

View full text Add to dashboard Cite

A transportable prototype Faraday rotation spectroscopic system based on a tunable external cavity quantum cascade laser has been developed for ultrasensitive detection of nitric oxide (NO). A broadly tunable laser source allows targeting the optimum Q 3/2(3/2) molecular transition at 1875.81 cm ؊1 of the NO fundamental band. For an active optical path of 44 cm and 1-s lock-in time constant minimum NO detection limits (1) of 4.3 parts per billion by volume (ppbv) and 0.38 ppbv are obtained by using a thermoelectrically cooled mercury-cadmium-telluride photodetector and liquid nitrogen-cooled indium-antimonide photodetector, respectively. Laboratory performance evaluation and results of continuous, unattended monitoring of atmospheric NO concentration levels are reported.external cavity laser ͉ nitric oxide detection ͉ midinfrared ͉ magnetic circular birefringence ͉ paramagnetic species I n this article, we describe the development and performance of a prototype transportable, cryogen-free spectroscopic sensing system for ultrasensitive detection of atmospheric nitric oxide (NO) based on Faraday rotation spectroscopy (FRS). The FRS technique as a method for improving sensitivity by reducing source noise was first reported in the 1980s with a color-center laser source (1). The recent availability of thermoelectrically cooled widely tunable continuous wave (CW) external cavity quantum cascade lasers (EC-QCLs) (2) makes feasible a transportable FRS NO sensor targeting the optimum Q 3/2 (3/2) NO absorption line of the fundamental vibration at 5.33 m that has great potential for development into a compact field-deployable system. Ultrasensitive trace gas detection is of increasing interest in various applications including environmental monitoring, industrial emission measurements, chemical analysis, medical diagnostics, and security. The combination of midinfrared, continuous wave, high-performance QCL sources with sensitive spectroscopic measurement techniques is leading to improved specificity, and lower minimum detection limits (MDLs) for many molecular species as compared with nonoptical chemical sensors. This work was made possible by recent advances in QCL fabrication technology that have resulted in Fabry-Perot QC laser chips with wide gain bandwidth and high-output power levels at room temperature (3). These developments permit the construction of widely tunable EC-QCLs like the one used here.Our development of an EC-QCL-based FRS spectrometer was motivated by the current need for monitoring and quantifying the significant increase of atmospheric NO concentration levels due to combustion emissions that are impacting air quality in urban environments worldwide. NO molecules play a major role in atmospheric chemistry and significantly contribute to the formation of photochemical smog and acid rain and to the depletion of the stratospheric ozone layer (4, 5). Furthermore, NO at low concentrations in human and mammalian cells is of great importance in the regulation of biological and physiological processes (6). ...

show abstract

“…The intensity fluctuations inherent to the light source can be fought by dual acquisition 30 or by heterodyne detection. 31,32 When the reactant dissociates, usually, at least one of the photofragments can be observed optically with a good efficiency giving potentially access to the same information as direct absorption.…”

Section: Introductionmentioning

confidence: 99%

Photodissociation resonances of jet-cooled NO2 at the dissociation threshold by CW-CRDS

Dupré

2015

The Journal of Chemical Physics

View full text Add to dashboard Cite

Around 398 nm, the jet-cooled-spectrum of NO2 exhibits a well identified dissociation threshold (D0). Combining the continuous-wave absorption-based cavity ringdown spectroscopy technique and laser induced fluorescence detection, an energy range of ∼25 cm(-1) is analyzed at high resolution around D0. In addition to the usual molecular transitions to long-lived energy levels, ∼115 wider resonances are observed. The position, amplitude, and width of these resonances are determined. The resonance width spreads from ∼0.006 cm(-1) (i.e., ∼450 ps) to ∼0.7 cm(-1) (∼4 ps) with large fluctuations. The identification of at least two ranges of resonance width versus the excess energy can be associated with the opening of the dissociation channels NO2→NO(X(2)Π1/2, v=0, J=1/2+O((3)P2) and NO2→NO(X(2)Π1/2, v=0, J=3/2)+O((3)P2). This analysis corroborates the existence of loose transition states close to the dissociation threshold as reported previously and in agreement with the phase space theory predictions as shown by Tsuchiya's group [Miyawaki et al., J. Chem. Phys. 99, 254-264 (1993)]. The data are analyzed in the light of previously reported frequency- and time-resolved data to provide a robust determination of averaged unimolecular dissociation rate coefficients. The density of reactant levels deduced (ρreac ∼ 11levels/cm(-1)) is discussed versus the density of transitions, the density of resonances, and the density of vibronic levels.

show abstract

Trace detection of NO_2 by frequency-modulation-enhanced magnetic rotation spectroscopy

Cited by 30 publications

References 13 publications

Tunable mid-infrared laser absorption spectroscopy

Tunable mid-infrared laser absorption spectroscopy

Ultrasensitive detection of nitric oxide at 5.33 μm by using external cavity quantum cascade laser-based Faraday rotation spectroscopy

Photodissociation resonances of jet-cooled NO2 at the dissociation threshold by CW-CRDS

Contact Info

Product

Resources

About