Download or read book Development of a Quantum Cascade Laser Based Detector for Ammonia and Nitric Acid written by and published by . This book was released on 2005 with total page 43 pages. Available in PDF, EPUB and Kindle. Book excerpt: We have developed a compact, robust, atmospheric trace gas detector based on mid-infrared absorption spectroscopy using pulsed quantum cascade (QC) lasers. The spectrometer is suitable for airborne measurements of ammonia, nitric acid, formaldehyde, formic acid, methane, nitrous oxide, carbon monoxide, nitrogen dioxide and other gases that have line-resolved absorption spectra in the mid-infrared spectral region. The QC laser light source operates near room temperature with thermal electric cooling instead of liquid nitrogen which has been previously required for semiconductor lasers in the mid-infrared spectral region. The QC lasers have sufficient output power so that thermal electric cooled detectors may be used in many applications with lower precision requirements. The instrument developed in this program has been used in several field campaigns from both the Aerodyne Mobile Laboratory and from the NOAA WP3 aircraft. The Phase II program has resulted in more than 10 archival publications describing the technology and its applications. Over 12 instruments based on this design have been sold to research groups in Europe and the United States making the program both a commercial as well as a technological success. Anticipated Benefits The development of a sensitive, cryogen-free, mid-infrared absorption method for atmospheric trace gas detection will have wide benefits for atmospheric and environmental research and broader potential commercial applications in areas such as medical diagnostic and industrial process monitoring of gaseous compounds. Examples include air pollution monitoring, breath analysis, combustion exhaust diagnostics, and plasma diagnostics for semi-conductor fabrication. The substitution of near-room temperature QC lasers for cryogenic lead salt TDLs and the resulting simplifications in instrument design and operation will greatly expand the range of applications.

Download or read book Trace Gas Spectrometry Using Quantum Cascade Lasers written by David Wilson and published by . This book was released on 2012 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This project was initially the continuation of a previous PhD students work. This changed slightly to incorporate the initial steps of development of a new system. However the main underlying focus was the absorption of infrared light by molecular gases using a still relatively new light source. This thesis will present the results of experimental work carried out during studies on the detection of gases and the nonlinear optical effects that arise from the absorption of light from a rapid frequency swept laser. A bench mounted two channel quantum cascade laser absorption spectrometer was used during experiments to observe and reduce nonlinear effects that arise from tuning the lasers during the absorption of light by several atmospherically important gases. These gases include the oxides of nitrogen (nitrous oxide, nitrogen dioxide and nitric oxide), methane and ammonia. The pulsed laser systems used as part of the spectrometer have also been put to use performing measurements on gaseous hydrocarbon combustion (methane and ethylene flames), to determine the feasibility of making measurements within the combustion zone of a jet engine and in conjunction with a continuous wave device during pump-probe experiments at the Chemistry Department of Oxford University. A portable four channel spectrometer was used at the beginning of the project to make measurements of the exhaust fumes of diesel powered vehicles. It will also cover the initial steps and tests performed in the early stages of development of a continuous wave quantum cascade laser based spectrometer for high speed detection of trace gases.

Download or read book The Application of Quantum Cascade Lasers to Mid infrared Gas Sensing written by Paul Richie Black and published by . This book was released on 2011 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis explains the development of a quantum cascade laser based gas sensor and the verification of performance of the resulting product. The capability to detect trace levels of multiple species in varying physical conditions, specifically high temperature is shown.Optical designs capable of allowing the measurement technique to be used in a variety of applications have been developed, specifically multi-pass gas absorption cells. The accurate, precise and high speed analysis of the resulting data is made possible by spectral analysis algorithms. These developments and techniques were then applied to high temperature spectroscopic measurements. Spectra recorded at Rutherford Appleton Laboratory were used to calibrate high temperature measurements. The performance of the technology was thoroughly tested at the National Physical Laboratory. The resulting sensors have since been used to study the exhaust gases produced by a variety engine types ranging from cars to ships as well as atmospheric measurements.

Download or read book Spectroscopy System Based on a Single Quantum Cascade Laser for Simultaneous Detection of CO and CO2 Project Supported by the National Key Scientific Instrument and Equipment Development Project of China Grnat No 2014YQ060537 the National Basic Research Program of China Grant No 2013CB632803 the Strategic Priority Research Program of the Chinese Academy of Sciences Grant No XDA05040102 and the National Natural Science Foundation of China Grant No 41405134 written by and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: A quantum cascade laser (QCL) based system for simultaneous detection of CO and CO2 is developed. The QCL can scan over two neighboring CO (2055.40 cm −1 ) and CO2 (2055.16 cm −1 ) lines with a single current scan. The wavelength modulation spectroscopy ( f = 20 kHz) is utilized to enhance the signal-to-noise ratio. A white cell with an effective optical path length of 74 m is used. The calibration of the sensor is performed and minimum detection limits of 1.3 ppb (1 × 10 −9 ) for CO and 0.44 ppm (1 × 10 −6 ) for CO2 are achieved.

Download or read book Principles and development of tunable diode laser spectroscopy for measuring fluxes of ammonia and nitric acid written by M M. Twigg and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Quantum Cascade Laser Based Absorption Spectrometer for Trace Gas Molecular Detection and Nonlinear Optics written by Michael Telfer McCulloch and published by . This book was released on 2006 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Remote Chemical Sensing Using Quantum Cascade Lasers written by Warren W. Harper and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Development of Quantum Cascade Lasers for Gas Sensing Applications written by Deivis Vaitiekus and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book New Developments in GaAs based Quantum Cascade Lasers written by Chris Atkins and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Quantum Cascade Laser Spectroscopy written by Richard Walker and published by . This book was released on 2011 with total page 306 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book FY 2005 Quantum Cascade Laser Alignment System Final Report written by Tanya L. Myers and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Quantum Cascade Laser Spectroscopy written by Tomás Henrique Passos Pinto and published by . This book was released on 2018 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Development of a System for Coherent Continuous wave Detection of Radiation from a Terahertz Quantum Cascade Laser written by Aziati Husna Awang and published by . This book was released on 2012 with total page 464 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Quantum Cascade Laser Spectroscopy written by Richard James Walker and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Quantum Cascade Laser Spectroscopy written by Tomás Henrique Passos Pinto and published by . This book was released on 2018 with total page 188 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Intersubband Quantum Cascade Infrared Laser Development Phase 1 written by and published by . This book was released on 1996 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objectives of this program were threefold: to reproduce the quantum cascade laser results from Bell Labs in a production environment, to demonstrate the quantum cascade laser at longer wavelengths, and to extend the technology to the GaAs/AlGaAs material system in order to make the lasers easier to produce. After characterization with 5-crystal x-ray diffraction and photoluminescence to verify the material quality three laser wafers, with anticipated operating wavelengths near 4.5 microns and 8.5 microns, were grown, processed, and tested for this program. Although we were able to successfully grow the very thick lattice matched layers necessary for these devices, no lasing or electroluminescence was observed from any of the samples. Another laser design was produced based on the reported quantum cascade laser structures, but utilizing GaAs and AlGaAs materials instead of InGaAs and InAlAs; however, because of the negative results with the InGaAs/InAlAs structure and additional design uncertainties for the AlGaAs materials, this structure was not grown. This report will discuss in detail the work that was performed on the contract, possible cause for the negative results, and conclusions drawn from the work.

Download or read book Widely Tunable and SI traceable Frequency comb stabilised Mid infrared Quantum Cascade Laser written by Dang Bao An Tran and published by . This book was released on 2019 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The thesis consists in developing a high-resolution mid-infrared spectrometer traceable to primary frequency standards and providing a unique combination of resolution, tunability, detection sensitivity and frequency control. A quantum cascade laser (QCL) emitting at 10.3 μm is phase locked to an optical frequency comb stabilized to a remote 1.55 μm ultra-stable reference developed at LNE-SYRTE, monitored against primary frequency standards and transferred to LPL via an active noise compensated fibre link. This results in a 0.1 Hz QCL linewidth, a stability below 10−15 at 1 s and an uncertainty on its absolute frequency below 4 × 10−14. Moreover, the setup allows the QCL to be widely scanned over 1.4 GHz while maintaining the highest stabilities and precision. This QCL was used to carry out saturated absorption spectroscopy of several molecules in a compact multipass cell. We demonstrated statistical uncertaintyon line-center frequencies at the kHz level and sub-10 kHz systematic uncertainty. We have recorded several singular K-doublets and many rovibrational transitions of methanol, in particular weak transitions and weak doublets - unreported so far. Precise parameters modelling trioxaneh ave been determined with only a few tens of rovibrational transitions recorded at unprecedented accuracy. The quadrupole hyperfine structure of an ammonia transition has been resolved for thefirst time. This setup constitutes a key element for the project aiming at the first observation of parity violation in molecules currently held at LPL, and, more generally, for various fields of physics, from atmospheric and interstellar physics to fundamental physics beyond the standard model.