Quantum cascade lasers in chemical physics

Curl, R. F.; Capasso, Federico; Gmachl, Claire F.; Kosterev, Anatoliy A.; McManus, Barry; Lewicki, R.; Pusharsky, Michael; Wysocki, Gerard; Tittel, Frank K.

doi:10.1016/j.cplett.2009.12.073

Cited by 498 publications

(256 citation statements)

References 135 publications

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“…More recently, advances in room temperature, distributedfeedback quantum cascade (QC) lasers have led to the development of QC-laser-based NH 3 sensors using the strongest NH 3 absorption transitions located in the mid-infrared spectral region (Manne et al, 2006;Whitehead et al, 2007;McManus et al, 2008;Manne et al, 2009;Curl et al, 2010;Ellis et al, 2010;Gong et al, 2011). Although these closedpath systems are highly sensitive (ppbv or sub-ppbv), they suffer from sampling artifacts that limit precision and response time and complicate calibration methods (Whitehead et al, 2008;von Bobrutzki et al, 2010).…”

Section: J Miller Et Al: Open-path Qcl-based Ammonia Sensormentioning

confidence: 99%

Open-path, quantum cascade-laser-based sensor for high-resolution atmospheric ammonia measurements

et al. 2014

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Abstract. We demonstrate a compact, open-path, quantum cascade-laser-based atmospheric ammonia sensor operating at 9.06 µm for high-sensitivity, high temporal resolution, ground-based measurements. Atmospheric ammonia (NH 3 ) is a gas-phase precursor to fine particulate matter, with implications for air quality and climate change. Currently, NH 3 sensing challenges have led to a lack of widespread in situ measurements. Our open-path sensor configuration minimizes sampling artifacts associated with NH 3 surface adsorption onto inlet tubing and reduced pressure sampling cells, as well as condensed-phase partitioning ambiguities. Multi-harmonic wavelength modulation spectroscopy allows for selective and sensitive detection of atmospheric pressurebroadened absorption features. An in-line ethylene reference cell provides real-time calibration (±20 % accuracy) and normalization for instrument drift under rapidly changing field conditions. The sensor has a sensitivity and noise-equivalent limit (1σ ) of 0.15 ppbv NH 3 at 10 Hz, a mass of ∼ 5 kg and consumes ∼ 50 W of electrical power. The total uncertainty in NH 3 measurements is 0.20 ppbv NH 3 ± 10 %, based on a spectroscopic calibration method. Field performance of this open-path NH 3 sensor is demonstrated, with 10 Hz time resolution and a large dynamic response for in situ NH 3 measurements. This sensor provides the capabilities for improved in situ gas-phase NH 3 sensing relevant for emission source characterization and flux measurements.

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Section: J Miller Et Al: Open-path Qcl-based Ammonia Sensormentioning

confidence: 99%

Open-path, quantum cascade-laser-based sensor for high-resolution atmospheric ammonia measurements

et al. 2014

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“…The UAV sensors can be used for satellite validation in the atmospheric boundary layer, horizontal and vertical mapping of local pollutants and greenhouse gases, meteorology, and understanding ecosystem dynamics (e.g., carbon uptake in a forest canopy). In addition, with only slight modifications to the sensors described in this project, mid-infrared quantum cascade laser sensors can be developed to probe a larger suite of trace gas species that have higher sensitivity and selectivity in the mid-infrared spectral region [23]. Future efforts include developing an in-line reference cell and numerical algorithms to improve stability and long-term precision to levels approaching our current 1 Hz precision, increased software functionality for spectral analyses and concentration values reported in real-time, and more robust intercomparisons with other sensors.…”

Section: Discussionmentioning

confidence: 99%

Low Power Greenhouse Gas Sensors for Unmanned Aerial Vehicles

et al. 2012

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Abstract:We demonstrate compact, low power, lightweight laser-based sensors for measuring trace gas species in the atmosphere designed specifically for electronic unmanned aerial vehicle (UAV) platforms. The sensors utilize non-intrusive optical sensing techniques to measure atmospheric greenhouse gas concentrations with unprecedented vertical and horizontal resolution (~1 m) within the planetary boundary layer. The sensors are developed to measure greenhouse gas species including carbon dioxide, water vapor and methane in the atmosphere. Key innovations are the coupling of very low power vertical cavity surface emitting lasers (VCSELs) to low power drive electronics and sensitive multi-harmonic wavelength modulation spectroscopic techniques. The overall mass of each sensor is between 1-2 kg including batteries and each one consumes less than 2 W of electrical power. In the initial field testing, the sensors flew successfully onboard a T-Rex Align 700E robotic helicopter and showed a precision of 1% or less for all three trace gas species. The sensors are battery operated and capable of fully automated operation for long periods of time in diverse sensing environments. Laser-based trace gas sensors for UAVs allow for high spatial mapping of local greenhouse gas OPEN ACCESSRemote Sens. 2012, 4 1356 concentrations in the atmospheric boundary layer where land/atmosphere fluxes occur. The high-precision sensors, coupled to the ease-of-deployment and cost effectiveness of UAVs, provide unprecedented measurement capabilities that are not possible with existing satellite-based and suborbital aircraft platforms.

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“…Recently infrared spectroscopy has shown progress in the use of more powerful IR sources, such as Quantum Cascade Lasers (QCL) by incorporating these devices in IR reflectance, IR transmission and even in IR microscopy applications [24]. QCL-based setups are being developed for in the field applications such as breath analysis, environmental research, airborne measurements, security applications, laser-based isotope ratio measurements, and many others.…”

Section: Introductionmentioning

confidence: 99%