Tittel2 1state key laboratory of integrated optoelectronics, college of electronic science and engineering, jilin university, 2699 qianjin street, changchun 012, china. Validation of the doubly labeled water method using offaxis. Oaicos involves no sample conversion and has a small footprint, allowing measurements to be made by researchers collecting the samples. With crds, a laser pulse is trapped in a highly reflective optical cavity. In the field of laserbased absorption spectroscopy, off axis integrated cavity output spectroscopy is considered to be a sensitive and robust method, employing a simple optical design. Noinfluenceofco onstableisotopeanalysesofsoilwaterswith. There are two commercially available forms of laser absorption spectroscopy for water isotope analysis, cavity ringdown spectroscopy crds and offaxis integrated cavity output spectroscopy oaicos.
The instrument employs an offaxis trajectory of the laser beam through the cell to yield an effective optical path length of several kilometers without significant. Offaxis integrated cavity output spectroscopy and its. The specific analyzer technology, called off axis integrated cavity output spectroscopy oaicos, accurately measures the three stable isotopes of water liquid and vapor. Tittel2 1state key laboratory of integrated optoelectronics, college of electronic science and engineering, jilin university, 2699 qianjin street, changchun 012. Novel and automated preparation systems such as continuous flow isotope ratio mass spectrometry, offaxis integrated cavity output spectroscopy for isotopic compositions of selected molecules, multicollector inductively coupledplasma mass spectrometry icpms, triple quadrupole. A nearinfrared c2h2ch4 dualgas sensor system combining. The laserbased sensor employed a 44 cm optical cavity that provided an effective absorption path length of. According to the property of optical cavity and the principle of signals and systems, the mathematical derivations for wavelength modulation offaxis integrated cavity output spectroscopy wmoaicos are presented.
The study of wavelength modulation offaxis integrated. Based upon the property of optical cavity and the principle of signals and systems, the measural theory and signal expression of off axis integrated cavity output spectroscopy off axis icos have been analyzed and deduced. Both analyzer systems use the absorption of a nearinfrared laser beam by molecules i. A times improvement in signaltonoise ratio is achieved using a reinjection mirror and a minimum detection limit.
An ultrasensitive laserabsorption spectrometer, based on offaxis integrated cavity output spectroscopy, was utilized to measure the stable isotopes of hydrogen. Integrated cavity output spectroscopy icos and cavity enhanced absorption spectroscopy ceas. In this letter, a new method is proposed to further improve the detection sensitivity of the gas sensor based on offaxis integrated cavity spectroscopy oaicos using a distributed feedback laser operating in the nearinfrared at 1653 nm that relies on implementation of wavelength modulation and radio frequency rf white noise perturbation to diode laser current. Midinfrared quantum cascade laser based offaxis integrated. Nearinfrared acetylene sensor system using off axis integrated cavity output spectroscopy and two measurement schemes kaiyuan zheng, 1 chuantao zheng,1, qixin he,1 dan yao,1 lien hu,1 yu zhang, 1 yiding wang,1 and frank k. Offaxis integrated cavity output spectroscopy oaicos.
Advances in the use of isotopes in geochemical exploration. Melanson1, tracy swibas1, victoria catenacci1, john r. Osa highsensitivity offaxis integrated cavity output. Off axis integrated cavity output spectroscopy with a midinfrared interband cascade laser for realtime breath ethane measurements. Off axis integrated cavity output spectroscopy oaicos has generated much interest because it potentially allows highly sensitive field measurements with robust optical alignment. Enhancing offaxis integrated cavity output spectroscopy. For highly sensitive and accurate acetylene c 2 h 2 detection, a nearinfrared nir offaxis integratedcavity output spectroscopy oaicos sensor system based on an ultracompact cagebased absorption cell was proposed. A new variation of the cavity ringdown spectroscopy technique was developed independently in 1998 in two different groups by okeefe et al. The instrument utilizes quantum cascade laser qcl in the 7. Nearinfrared acetylene sensor system using off axis integrated cavity output spectroscopy and two measurement schemes kaiyuan zheng, 1 chuantao zheng,1, qixin he,1 dan yao,1 lien hu,1. Mode noise suppression in off axis integrated cavity output spectroscopy oaicos is a key for improving the signaltonoise ratio snr of a sensor system, which basically depends on the ability to smooth out the cavity mode structure and to reduce the cavity mode linewidth. A continuouswave, midinfrared, distributed feedback, interband cascade laser was used to detect and quantify formaldehyde h 2 co using offaxis, integrated cavity output spectroscopy in gas mixtures containing. Pdf nearinfrared methane sensor system using offaxis.
Since the 1950s, geologists have used analysis of the stable isotope ratios of certain elements, such. Nearinfrared methane sensor system using offaxis integrated. H 2 s trace concentration measurements using offaxis. Offaxis integrated cavity output spectroscopy oaicos holds promise for locating mineral deposits. Apr 01, 2010 based upon the property of optical cavity and the principle of signals and systems, the measural theory and signal expression of off axis integrated cavity output spectroscopy off axis icos have been analyzed and deduced. Nov 05, 20 in this work we demonstrate for the first time the use of offaxis integrated cavity output spectroscopy oaicos to directly measure. A midinfrared trace gas detection system based on offaxis integrated cavity output spectroscopy oaicos is demonstrated for accurate and sensitive detection of n2o in combination with a continuous wave externalcavity quantum cascade laser ecqcl working around 7. Recently, there has been increasing interest in measurement and use of the lessabundant 17o isotope in addition to 2h and 18o. And based on the analytical method, the function expression of wmoaicos signal from lorentzian absorption profile is obtained. An ultrasensitive laser absorption spectrometer based on offaxis integrated cavity output spectroscopy was demonstrated for simple and inexpensive measurement of stable isotopes in natural isotopic abundance and isotopically enriched human urine. The oaicos cavity consisted of two 1\textquotedbl high reflectivity spherical mirrors with 1 m radius of curvature, separated by a 0. Heterodyne offaxis integrated cavity output spectroscopy. A midinfrared trace gas detection system based on offaxis integrated cavity output spectroscopy oaicos is demonstrated for accurate and sensitive detection of n2o in combination with a continuous wave external cavity quantum cascade laser ecqcl working around 7.
This lgrpatented technique offers superior performance, value and reliability compared to cavity ringdown spectroscopy crds. Validation of the doublylabeled water method using integrated cavity output spectroscopy edward l. In brief, the beam of a nearinfrared diode laser is directed offaxis into an optical cavity. We discuss here design choices involved in design of an oaicos instrument and how these choices impact instrument sensitivity, using as our example the design of the harvard icos isotope instrument, which. With crds, a laser pulse is trapped in a highly re. Using offaxis integrated cavity output spectroscopy oaicos, we use a small cell size 25 cm in length to achieve a fast flush time 50hz and therefore higher potential sampling rate of the instrument. Unique laser absorption technology called offaxis integrated cavity output spectroscopy oaicos first developed cavity ring down spectroscopy crds in 1988 by anthony okeefe founder of lgr 4th generation delivers superior performance, and is ordersof. Kaul1, zhi ning1,2, dane westerdahl2, xijie yin3, robert a. Pdf on apr 1, 2020, kaiyuan zheng and others published nearinfrared methane sensor system using off axis integrated cavity output spectroscopy with novel dualinput dual output coupling scheme. A midinfrared trace gas detection system based on off axis integrated cavity output spectroscopy oaicos is demonstrated for accurate and sensitive detection of n2o in combination with a continuous wave external cavity quantum cascade laser ecqcl working around 7. Berman3 1university of colorado anschutz medical campus, aurora, co, 2university of aberdeen, ab erdeen, scotland, uk and chinese academy of sciences, beijing. In this work we demonstrate for the first time the use of offaxis integrated cavity output spectroscopy oaicos to directly measure. Cary4 1 school of energy and environment, city university of hong kong, hong kong.
For highly sensitive and accurate acetylene c2h2 detection, a nearinfrared nir offaxis integrated cavity output spectroscopy oaicos sensor system based on an ultracompact cagebased absorption cell was proposed. Validation of the doublylabeled water method using. Nov 20, 2012 an ultrasensitive laserabsorption spectrometer, based on offaxis integrated cavity output spectroscopy, was utilized to measure the stable isotopes of hydrogen. Aug 16, 2008 off axis integrated cavity output spectroscopy oaicos has generated much interest because it potentially allows highly sensitive field measurements with robust optical alignment. Nearinfrared acetylene sensor system using offaxis integrated cavity output spectroscopy and two measurement schemes kaiyuan zheng, 1 chuantao zheng,1, qixin he,1 dan yao,1 lien hu,1 yu zhang, 1 yiding wang,1 and frank k. Noinfluenceofco onstableisotopeanalysesofsoilwaterswith off. Validation of the doubly labeled water method using off. The exponential decay of the light intensity is measured ringdown time and used to calculate the concentration of the absorbing substance in the gas mixture in the cavity. By combining frequency division multiplexing assisted wavelength modulation spectroscopy fdmwms and offaxis integrated cavity output spectroscopy oaicos, a nearinfrared nearir dualgas sensor system was demonstrated for simultaneous chemical gas. Open access publications 51530 freely accessible full text publications. Offaxis integrated cavity output spectroscopy oaicos is demonstrated for accurate and precise measurements. In brief, the beam of a nearinfrared diode laser is directed off axis into an optical cavity. Oaicos applied to oh detection motivations outlineoftalk introduction icos icosexpr.
Among the emerging techniques to detect the real footprint of buried ore deposits is isotope tracing. Hydrogen sulfide h2s trace detection has been performed by means of a dfb diode laserbased offaxis integrated cavity output spectroscopy oaicos near 1571. There are two commercially available forms of laser absorption spectroscopy for water isotope analysis, cavity ringdown spectroscopy crds and off axis integrated cavity output spectroscopy oaicos. Experimentalbased comparison between offaxis integrated. Off axis integrated cavity output spectroscopy oaicos holds promise for locating mineral deposits.
A novel tandem of thermal desorption carbon analyzer and off axis integrated cavity output spectroscopy for aerosol stable carbon isotope ratio measurement daya s. A midinfrared trace gas detection system based on off axis integrated cavity output spectroscopy oaicos is demonstrated for accurate and sensitive detection of n2o in combination with a. Experimentalbased comparison between off axis integrated cavity output spectroscopy and multipassassisted wavelength modulation spectroscopy at 7. Off axis integrated cavity output spectroscopy oaicos is demonstrated for accurate and precise measurements. A novel instrument based on an improved offaxis alignment of integrated cavity output spectroscopy oaicos in conjunction with a wavelength modulation wm technique, was developed using a dfb. A detailed description of this technique is given by baer et al. Oaicos involves no sample conversion and has a small. Pdf on apr 1, 2020, kaiyuan zheng and others published nearinfrared methane sensor system using offaxis integrated cavity output spectroscopy with novel dualinput dual output coupling scheme.
Detection of formaldehyde using offaxis integrated cavity. An injected volume correction factor is determined for each isotope and was applied to get more accurate data. The researchers who collect the samples can make the measurements. Abstracts of osu international symposium on molecular spectroscopy 201020. This item appears in the following collections faculty of science 27148. Unlike previous techniques, it requires no sample conversion with toxic reagents and is simple to operate. Rao and andreas karpf, extremely sensitive detection of no 2 employing offaxis integrated cavity output spectroscopy coupled with multipleline integrated absorption spectroscopy, appl. Offaxis integrated cavity output spectroscopy oaicos has generated much interest because it potentially allows highly sensitive field measurements with robust optical alignment. A nearinfrared c2h2ch4 dualgas sensor system combining off. Development of an offaxis integrated cavity output. This approach enables absorption spectra to be obtained through the integration of the total light signal transmitted through the. A novel instrument that employs a highfinesse optical cavity as an absorption cell has been developed for sensitive measurements of gas mixing ratios using nearinfrared diode lasers and absorption spectroscopy techniques. A midinfrared trace gas detection system based on offaxis integrated cavity output spectroscopy oaicos is demonstrated for accurate and sensitive detection of n2o in combination with a. The effect of the injected rf noise level on the cavity mode noise and the deformation of the absorption line shape in offaxis integrated cavity output spectroscopy oaicos with a distributed feedback laser dfb at 1.
Crds and offaxis integrated cavity output spectroscopy oaicos. Pdf intensity enhancement in offaxis integrated cavity. Osu international symposium on molecular spectroscopy. Unlike older laserbased methods, such as cavity ringdown spectroscopy crds, this approach utilizes true wavelength scanning to record fully resolved detailed absorption lineshapes, which are presented to the user in real time, a critical advantage that delivers several.
Mode noise suppression in offaxis integrated cavity output spectroscopy oaicos is a key for improving the signaltonoise ratio snr of a sensor system, which basically depends on the ability to smooth out the cavity mode structure and to reduce the cavity mode linewidth. Nearinfrared acetylene sensor system using offaxis. Application of the method to mineral water bottles sold in india showed that it is. Rapid, noninvasive, and nondestructive method for biofilm imaging on metallic surfaces using active thermography. Ct offaxis integrated cavity output spectroscopyoaicos has generated much interest because it potentially allows highly sensitive. Offaxis integrated cavity output spectroscopy oaicos all lgr analyzers utilize a unique laser absorption technology called offaxis integrated cavity output spectroscopy oaicos. Based upon the property of optical cavity and the principle of signals and systems, the measural theory and signal expression of offaxis integrated cavity output spectroscopy offaxis icos have been analyzed and deduced. Berman, lindsay liebson,2 and manish gupta1,a 1los gatos research, 67 east evelyn avenue, suite 3, mountain view, california 940411518, usa. Hydrogen sulfide h 2 s trace detection has been performed by means of a dfb diode laserbased offaxis integrated cavity output spectroscopy oaicos near 1571. A novel instrument based on an improved offaxis alignment of integrated cavity output spectroscopy oaicos in conjunction with a wavelength modulation wm technique, was developed using a dfb diode laser operating in the near infrared at 1. Osa nearinfrared acetylene sensor system using offaxis. Intensity enhancement in offaxis integrated cavity output.
However, one of the major drawbacks of nonmodematched cavities combined with highly reflective mirrors 99. Recently, there has been increasing interest in measurement and use of the lessabundant 17 o isotope in addition to 2 h and 18 o. Pdf offaxis integrated cavity output spectroscopy with a. Abstract offaxis integrated cavity output spectroscopy oaicos has generated much interest because it potentially allows highly sensitive. By combining frequency division multiplexing assisted wavelength modulation spectroscopy fdmwms and off axis integrated cavity output spectroscopy oaicos, a nearinfrared nearir dualgas sensor system was demonstrated for simultaneous chemical gasphase detection of acetylene c2h2 and methane ch4. In the field of laserbased absorption spectroscopy, offaxis integrated cavity output spectroscopy is considered to be a sensitive and robust method, employing a simple optical design. Pdf sensitivity enhancement in offaxis integrated cavity. Nov 29, 2012 the present application claims the benefit of the filing date of u. The analyzer had a small footprint and simple, inexpensive operation, allowing. Design considerations in highsensitivity offaxis integrated.
Offaxis integrated cavity output spectroscopy with a midinfrared interband cascade laser for realtime breath ethane measurements. Pdf design considerations in highsensitivity offaxis. Jthd78 h2s trace detection using offaxis integrated cavity. Stable isotopes of water have long been used to improve understanding of the hydrological cycle, catchment hydrology, and polar climate. Pdf offaxis integrated cavity output spectroscopy with. In the present work, we demonstrate the feasibility of h2s trace detection by means of off axis integrated cavity output spectroscopy oaicos using a dfb diode laser near 1571. Wavelength modulated offaxis integrated cavity output. A novel tandem of thermal desorption carbon analyzer and off. Cavity enchanced absorption spectroscopy ceas or integrated. Integrated cavity output spectroscopy icos sometimes called as cavity enhanced absorption spectroscopy ceas records the integrated intensity behind one of the cavity mirrors, while the laser is repeatedly swept across one or several cavity modes.
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