Download or read book Targeted Gas Spectroscopy Using Tunable VCSELs written by and published by . This book was released on 2011 with total page 1 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Multiplexed Gas Spectroscopy Using Tunable VCSELs written by and published by . This book was released on 2012 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: Detection and identification of gas species using tunable laser diode laser absorption spectroscopy has been performed using vertical cavity surface emitting lasers (VCSEL). Two detection methods are compared: direct absorbance and wavelength modulation spectroscopy (WMS). In the first, the output of a DC-based laser is directly monitored to detect for any quench at the targeted specie wavelength. In the latter, the emission wavelength of the laser is modulated by applying a sinusoidal component on the drive current of frequency?, and measuring the harmonics component (2?) of the photo-detected current. This method shows a better sensitivity measured as signal to noise ratio, and is less susceptible to interference effects such as scattering or fouling. Gas detection was initially performed at room temperature and atmospheric conditions using VCSELs of emission wavelength 763 nm for oxygen and 1392 nm for water, scanning over a range of approximately 10 nm, sufficient to cover 5-10 gas specific absorption lines that enable identification and quantization of gas composition. The amplitude and frequency modulation parameters were optimized for each detected gas species, by performing two dimensional sweeps for both tuning current and either amplitude or frequency, respectively. We found that the highest detected signal is observed for a wavelength modulation amplitude equal to the width of the gas absorbance lines, in good agreement with theoretical calculations, and for modulation frequencies below the time response of the lasers (
Download or read book Compact Laser spectroscopic Gas Sensors Using Vertical cavity Surface emitting Lasers written by Jia Chen and published by . This book was released on 2011 with total page 150 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Green Electronics written by Cristian Ravariu and published by BoD – Books on Demand. This book was released on 2018-06-20 with total page 254 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Green Electronics book is intended to stimulate people's thinking toward the new concepts of an environment-friendly electronics - the main challenge in the future. The book offers multiple solutions to push the classical electronic industry toward green concepts, aided by nanotechnologies, with revolutionary features that provide low power consumption in electronics, use biomaterials for integrated structures, and include environmental monitoring tools. Based on organic semiconductors/insulators without toxic precursors, green electronic technologies launched promising devices like OLED, OTFT, or nano-core-shell transistors. The Green Electronics book successfully presents the recent directions collected worldwide and leaves free space for continuing year by year with new subtopics.
Download or read book Laser Absorption Spectroscopy Techniques for Determining Gas Properties in High Pressure Rocket Combustors written by Daniel D Lee and published by . This book was released on 2020 with total page 161 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation describes laser absorption spectroscopy methods developed for temperature and carbon oxide (CO and CO2) sensing in high-pressure, fuel-rich combustion conditions of hydrocarbon-fueled bipropellant rockets. The scope of the work includes fundamental studies of spectroscopic interactions at high gas density, development of unique laser tuning and signal processing methods, and application of prototype sensors to rocket combustion devices under investigation at the Air Force Research Laboratory in Edwards, CA. Infrared vibrational spectra of CO and CO2 were probed using tunable semi-conductor lasers to infer gas properties. Initial sensor design targeted the absorption spectra of CO near 4.98 m, selected to minimize spectral interference with other combustion gas species at the extreme temperatures (> 3000 K) and pressures (> 50 atm) of a kerosene-fueled rocket combustion environment. Successful measurements were conducted up to 70 bar utilizing a scanned wavelength modulation spectroscopy technique, creating a new pressure-limit for quantitative in situ species sensing in a combustion device. At higher pressures (which were tested), collisional-broadening effects blended the targeted absorption transitions, causing differential absorption to diminish and reducing the signal-to-noise ratio of the measurements. To overcome the pressure-constraints, a more advanced laser absorption sensing strategy was developed, targeting the vibrational bandheads of CO near 2.3 m and CO2 near 4.2 m and exploiting the band narrowing effects of collisional line mixing to counter collisional broadening. Spectral line mixing--typically observed at high gas densities in which intermolecular collisions are sufficiently frequent and strong to cause a shift in energy level populations--corresponds to a transfer of absorption intensity from weak to strong absorption regions, inducing a narrowing of spectral features. This non-ideal phenomenon is more prominent in spectrally dense regions, such as bandheads. Targeting infrared bandheads to exploit line mixing, measurements of CO and CO2 concentration were demonstrated over a range of high pressures up to 105 bar in a single-element-injector RP-2/CH4-GOx rocket combustor. To make such measurements quantitative,spectroscopic models accounting line mixing effects have been developed utilizing a high-enthalpy shock tube; these models are then employed for interpretation of measured absorption signals for quantitative temperature and species sensing.
Download or read book Spectroscopy and Optical Diagnostics for Gases written by Ronald K. Hanson and published by Springer. This book was released on 2016-08-23 with total page 279 pages. Available in PDF, EPUB and Kindle. Book excerpt: This text provides an introduction to the science that governs the interaction of light and matter (in the gas phase). It provides readers with the basic knowledge to exploit the light-matter interaction to develop quantitative tools for gas analysis (i.e. optical diagnostics) and understand and interpret the results of spectroscopic measurements. The authors pair the basics of gas‐phase spectroscopy with coverage of key optical diagnostic techniques utilized by practicing engineers and scientists to measure fundamental flow‐field properties. The text is organized to cover three sub‐topics of gas‐phase spectroscopy: (1) spectral line positions, (2) spectral line strengths, and (3) spectral lineshapes by way of absorption, emission, and scattering interactions. The latter part of the book describes optical measurement techniques and equipment. Key subspecialties include laser induced fluorescence, tunable laser absorption spectroscopy, and wavelength modulation spectroscopy. It is ideal for students and practitioners across a range of applied sciences including mechanical, aerospace, chemical, and materials engineering.
Download or read book Optoelectronics Engineering and Information Technologies in Industry written by D.A. Li and published by Trans Tech Publications Ltd. This book was released on 2013-09-18 with total page 2320 pages. Available in PDF, EPUB and Kindle. Book excerpt: Collection of selected, peer reviewed papers from the 2013 2nd International Conference on Opto-Electronics Engineering and Materials Research (OEMR 2013), October 19-20, 2013, Zhengzhou, Henan, China. The 467 papers are grouped as follows: Chapter 1: Optoelectronic, Communication Technology and Applications; Chapter 2: Materials Science Engineering; Chapter 3: Mechatronics, Control and Management, Testing, Measurement and Monitoring Technologies; Chapter 4: Image Processing Technology and Methodology, Recognize Technologies; Chapter 5: Computing Methods and Algorithms, Automation and Information Technologies, CAD Applications.
Download or read book Absorption Spectroscopy of Combustion Gases Using a Tunable Diode Laser written by Patricia Kuntz Falcone and published by . This book was released on 1981 with total page 209 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Gas Sensing in Industry by Tunable Diode Laser Spectroscopy TDLS written by Maximilian Lackner and published by . This book was released on 2008 with total page 115 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Tunable Optoelectronic Devices written by Carlos Fernando Rondina Mateus and published by . This book was released on 2004 with total page 480 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Photoacoustic Spectroscopy on Gases with a Continuously Tunable High Pressure CO2 Laser written by Philippe Repond and published by . This book was released on 1995 with total page 111 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Photoacoustic spectroscopy on gases with a continously tunable high pressure CO2 laser written by Philippe Repond and published by . This book was released on 1995 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Handbook of Gas Sensor Materials written by Ghenadii Korotcenkov and published by Springer Science & Business Media. This book was released on 2013-09-18 with total page 454 pages. Available in PDF, EPUB and Kindle. Book excerpt: The two volumes of Handbook of Gas Sensor Materials provide a detailed and comprehensive account of materials for gas sensors, including the properties and relative advantages of various materials. Since these sensors can be applied for the automation of myriad industrial processes, as well as for everyday monitoring of such activities as public safety, engine performance, medical therapeutics, and in many other situations, this handbook is of great value. Gas sensor designers will find a treasure trove of material in these two books.
Download or read book State of the art Laser Gas Sensing Technologies written by Yufei Ma and published by MDPI. This book was released on 2020-03-05 with total page 278 pages. Available in PDF, EPUB and Kindle. Book excerpt: Trace gas sensing technologies are widely used in many applications, such as environmental monitoring, life science, medical diagnostics, and planetary exploration. On the one hand, laser sources have developed greatly due to the rapid development of laser media and laser techniques in recent years. Some novel lasers such as solid-state, diode, and quantum cascade lasers have experienced significant progress. At present, laser wavelengths can cover the range from ultraviolet to terahertz, which could promote the development of laser gas sensing technologies significantly. On the other hand, some new gas sensing methods have appeared, such as photothermal spectroscopy and photoacoustic spectroscopy. Laser spectroscopy-based gas sensing techniques have the advantages of high sensitivity, non-invasiveness, and allowing in situ, real-time observation. Due to the rapid and recent developments in laser source as well as the great merits of laser spectroscopy-based gas sensing techniques, this book aims to provide an updated overview of the state-of-the-art laser gas sensing technologies.
Download or read book Vertical cavity Surface emitting Lasers VIII written by Kent D. Choquette and published by SPIE-International Society for Optical Engineering. This book was released on 2004 with total page 270 pages. Available in PDF, EPUB and Kindle. Book excerpt: Proceedings of SPIE present the original research papers presented at SPIE conferences and other high-quality conferences in the broad-ranging fields of optics and photonics. These books provide prompt access to the latest innovations in research and technology in their respective fields. Proceedings of SPIE are among the most cited references in patent literature.
Download or read book Optical Engineering written by and published by . This book was released on 2006 with total page 970 pages. Available in PDF, EPUB and Kindle. Book excerpt: Publishes papers reporting on research and development in optical science and engineering and the practical applications of known optical science, engineering, and technology.
Download or read book Application of Tunable Diode and Other Infrared Sources for Atmospheric Studies and Industrial Process Monitoring written by and published by . This book was released on 1996 with total page 306 pages. Available in PDF, EPUB and Kindle. Book excerpt:
