Download or read book Advanced Laser Based Spectroscopic Techniques for Trace Gas Detection Based on Optical Cavity Enhancement and Multipass Absorption Cells written by Johnny Chung Leung Chu 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 Laser Spectroscopy for Sensing written by Matthieu Baudelet and published by Elsevier. This book was released on 2014-02-15 with total page 601 pages. Available in PDF, EPUB and Kindle. Book excerpt: Laser spectroscopy is a valuable tool for sensing and chemical analysis. Developments in lasers, detectors and mathematical analytical tools have led to improvements in the sensitivity and selectivity of spectroscopic techniques and extended their fields of application. Laser Spectroscopy for Sensing examines these advances and how laser spectroscopy can be used in a diverse range of industrial, medical, and environmental applications. Part one reviews basic concepts of atomic and molecular processes and presents the fundamentals of laser technology for controlling the spectral and temporal aspects of laser excitation. In addition, it explains the selectivity, sensitivity, and stability of the measurements, the construction of databases, and the automation of data analysis by machine learning. Part two explores laser spectroscopy techniques, including cavity-based absorption spectroscopy and the use of photo-acoustic spectroscopy to acquire absorption spectra of gases and condensed media. These chapters discuss imaging methods using laser-induced fluorescence and phosphorescence spectroscopies before focusing on light detection and ranging, photothermal spectroscopy and terahertz spectroscopy. Part three covers a variety of applications of these techniques, particularly the detection of chemical, biological, and explosive threats, as well as their use in medicine and forensic science. Finally, the book examines spectroscopic analysis of industrial materials and their applications in nuclear research and industry. The text provides readers with a broad overview of the techniques and applications of laser spectroscopy for sensing. It is of great interest to laser scientists and engineers, as well as professionals using lasers for medical applications, environmental applications, military applications, and material processing. Presents the fundamentals of laser technology for controlling the spectral and temporal aspects of laser excitation Explores laser spectroscopy techniques, including cavity-based absorption spectroscopy and the use of photo-acoustic spectroscopy to acquire absorption spectra of gases and condensed media Considers spectroscopic analysis of industrial materials and their applications in nuclear research and industry

Download or read book Fiber Laser System for the Detection of Trace Gas written by Jonas Kestutis Valiunas and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The research presented in this thesis is on the development of a trace gas detection system based on intracavity absorption spectroscopy (ICAS). The developed system was capable of detecting nitrous oxide (N2O) and acetylene (C2H2) gas at sub-ppmv levels. The P (12) rotational line of N2O at ~1522.20 nm, and the R (5) and R (4) rotational lines of C2H2 at ~1522.22 nm were used for detection. A fiber Bragg grating was incorporated into the ICAS cavity to enhance the system sensitivity by allowing the selection of strong absorption lines for detection. By operating the fiber laser based ICAS system at threshold, multiple circulations of the amplified spontaneous emission inside the cavity enhanced the system detection sensitivity. Further, the laser wavelength contained multi-longitudinal modes, which improved the system sensitivity. The system sensitivity was explored for two intra-cavity gas cells: a multi-pass Herriott cell and a gas cell based on a hollow-core photonic crystal fiber (HC-PCF). The system operated at room temperature and a polarization-maintaining erbium-doped fiber was used as a saturable absorber to help eliminate mode hopping in the laser cavity.

Download or read book Advanced Environmental Monitoring written by Young Kim and published by Springer Science & Business Media. This book was released on 2007-10-31 with total page 437 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book deals with recent developments and applications of environmental monitoring technologies, with emphasis on rapidly progressing optical and biological methods. Written by worldwide experts, this book will be of interest to environmental scientists in academia, research institutes, industry and the government.

Download or read book Laser and Fiber Optic Gas Absorption Spectroscopy written by George Stewart and published by Cambridge University Press. This book was released on 2021-04-08 with total page 276 pages. Available in PDF, EPUB and Kindle. Book excerpt: An invaluable text for the teaching, design, and development of gas sensor technology. This excellent resource synthesizes the fundamental principles of spectroscopy, laser physics, and photonics technology and engineering to enable the reader to fully understand the key issues and apply them in the design of optical gas absorption sensors. It provides a straightforward introduction to low-cost and highly versatile near-IR systems, as well as an extensive review of mid-IR systems. Fibre laser systems for spectroscopy are also examined in detail, especially the emerging technique of frequency comb spectroscopy. Featuring many examples of real-world application and performance, as well as MATLAB computer programs for modeling and simulation, this exceptional work is ideal for postgraduate students, researchers, and professional engineers seeking to gain an in-depth understanding of the principles and applications of fibre-optic and laser-based gas sensors.

Download or read book Handbook of Optoelectronics written by John P. Dakin and published by CRC Press. This book was released on 2017-10-05 with total page 444 pages. Available in PDF, EPUB and Kindle. Book excerpt: Handbook of Optoelectronics offers a self-contained reference from the basic science and light sources to devices and modern applications across the entire spectrum of disciplines utilizing optoelectronic technologies. This second edition gives a complete update of the original work with a focus on systems and applications. Volume I covers the details of optoelectronic devices and techniques including semiconductor lasers, optical detectors and receivers, optical fiber devices, modulators, amplifiers, integrated optics, LEDs, and engineered optical materials with brand new chapters on silicon photonics, nanophotonics, and graphene optoelectronics. Volume II addresses the underlying system technologies enabling state-of-the-art communications, imaging, displays, sensing, data processing, energy conversion, and actuation. Volume III is brand new to this edition, focusing on applications in infrastructure, transport, security, surveillance, environmental monitoring, military, industrial, oil and gas, energy generation and distribution, medicine, and free space. No other resource in the field comes close to its breadth and depth, with contributions from leading industrial and academic institutions around the world. Whether used as a reference, research tool, or broad-based introduction to the field, the Handbook offers everything you need to get started. John P. Dakin, PhD, is professor (emeritus) at the Optoelectronics Research Centre, University of Southampton, UK. Robert G. W. Brown, PhD, is chief executive officer of the American Institute of Physics and an adjunct full professor in the Beckman Laser Institute and Medical Clinic at the University of California, Irvine.

Download or read book Applications of Infrared Laser Spectroscopy to Breath Analysis written by Beth L. Cummings and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The work presented in this thesis is concerned with development of spectroscopic detection methods based on absorption spectroscopy using semiconductor lasers, with particular ref- erence to the field of medical diagnostics through breath analysis. The first part of this thesis deals with the design and testing of a prototype analyser for simultaneous monitoring of the exchange gases 02, C02 and H20 in breath. The aim of this analyser is to provide information required to monitor respiration, with potential use in intensive care monitoring or during anaesthesia. The relatively high concentrations of these gases in breath and read- ily available diode laser sources make detection in the near-infrared (NIR) ideal. However, the relatively weakly absorbing A-band 02 transitions at 760 nm require the application of a sensitive spectroscopic method, cavity enhanced absorption spectroscopy (CEAS). In contrast, CO2 and H20 are monitored using direct single pass absorption spectroscopy, with transitions arising from the 21/1 + 1/3 band at 2 uu: and 1/1 + 1/3 band at 1.3 p,m, re- spectively. It has been demonstrated that these gases can be detected simultaneously over a short pathlength (2.74 - 4 cm) in the respiratory flow by combining various spectroscopic methodologies and real-time data analysis. This analyser is shown to offer a viable alter- native for monitoring respiration, exhibiting absolute detection limits of changes of 0.26 % O2, 0.02 % CO2 and 0.003 % H20 with a 10 ms time resolution, which are comparable to current mass spectrometry based methods, but without their inherent delays. Following this, investigations into the detection of the main gas constituents in breath in the NIR employing noise-reduction modulation based spectroscopic techniques, namely wavelength and frequency modulation (WMS and FMS respectively) are also reported. The described WMS studies on water at 1.37 ust: provide a demonstration of conventional WMS detection, as well as a "proof-of-principle" example of a relatively new approach to calibrat- ing the non-absolute information obtained from a WMS absorption signal. Typically WMS spectra are calibrated using mixtures of known gas concentrations or an absolute direct absorption spectrum where possible. In this work however, a self-calibrating method, the phasor decomposition method (PDM), is employed and the returned concentration from this ~alibration is compared to direct absorption measurement. From this, the calculated concentration using the PDM is found to differ by 9 % from the concentration value ob- tained by direct absorption, providing an alternative method of calibration for when direct absorption measurements are not possible. The use of FMS in the NIR is also demon- strated as a potential alternative to CEAS for monitoring O2 at 760 nm. FMS detection is performed on atmospherically broadened 02 and a time-normalised O!min(t) of 2.45x10-6 cm-1 s~ is obtained, which is two orders of magnitude less sensitive than the value of 1 O!min(t) = 2.35x10-8 cm "! S2 obtained with CEAS. This combined with the experimental I requirements of an FMS system, make its use for detection of 02 a less practicable option compared to CEAS for real-time breath analysis. The latter work in this thesis involves a change in focus to detection of trace gases in breath in the mid-infrared (MlR). The move of spectroscopic detection to the MlR exploits the larger absorption cross-sections available in this region, and to achieve this, a relatively new form of semiconductor laser, the quantum cascade laser (QCL) is used. The design of a continuous wave QCL spectrometer at 8 usx: and its operating characteristics are demon- strated and improvements in its performances are also discussed. This QCL system is then utilised to demonstrate the potential of monitoring species in breath, namely the narrow- band absorber methane and the broadband absorber acetone, taking into consideration the potential interference from other absorbing species in breath and the different spectroscopic characteristics exhibited by these molecules. Finally, the potential to further improve the sensitive detection of trace gases in breath in the MlR is also investigated with studies on the use of CEAS and multipass cells. In this work, the molecule of interest is the biomarker OGS, using transitions of the 2V2 band at 1031 cm-I, that are probed using a 10 usx: QCL. The application of CEAS in the MlR is not as well developed as in the NIR, and the experimental consequences of using optical cavities at these wavelengths, where equipment tends to be more limited, are investigated and sensitivities discussed in the context of other literature. The experimental procedure of optimising a cavity for CEAS using the off-axis alignment method is also studied in detail, as well as the addition ofWMS to further improve the signal quality. An effective absorption pathlength of ,....., 100 m was achieved in the cavity, with a bandwidth reduced O!min(BW) 1 of 1.7x10-7 cm"? HZ-2 using WMS CEAS achieved. With the poorer quality optics and limitations in equipment in the MlR for CEAS experiments, the use of a multipass cell, a 238 m Herriott cell, is also investigated as an alternative to the use of an optical cavity at 10 tui". Detection of OCS using direct absorption and WMS is demonstrated in the 1 Herriott cell, achieving O!min(BW) = 2.03xlO-8 cm "! HZ-2 using WMS. This shows an improvement in sensitivity compared to WMS CEAS, and also shows the potential for future work on biomarker detection, as it approaches the r-- ppb levels required for breath analysis.

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 Environmental Trace Gas Detection Using Laser Spectroscopy written by and published by . This book was released on 1998 with total page 532 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Laser Induced Breakdown Spectroscopy written by Jagdish P. Singh and published by Elsevier. This book was released on 2007-10-03 with total page 455 pages. Available in PDF, EPUB and Kindle. Book excerpt: Laser induced breakdown spectroscopy (LIBS) is basically an emission spectroscopy technique where atoms and ions are primarily formed in their excited states as a result of interaction between a tightly focused laser beam and the material sample. The interaction between matter and high-density photons generates a plasma plume, which evolves with time and may eventually acquire thermodynamic equilibrium. One of the important features of this technique is that it does not require any sample preparation, unlike conventional spectroscopic analytical techniques. Samples in the form of solids, liquids, gels, gases, plasmas and biological materials (like teeth, leaf or blood) can be studied with almost equal ease. LIBS has rapidly developed into a major analytical technology with the capability of detecting all chemical elements in a sample, of real- time response, and of close-contact or stand-off analysis of targets. The present book has been written by active specialists in this field, it includes the basic principles, the latest developments in instrumentation and the applications of LIBS . It will be useful to analytical chemists and spectroscopists as an important source of information and also to graduate students and researchers engaged in the fields of combustion, environmental science, and planetary and space exploration. * Recent research work* Possible future applications* LIBS Principles

Download or read book Laser Spectroscopy of Solids II written by William M. Yen and published by Springer Science & Business Media. This book was released on 2006-01-21 with total page 319 pages. Available in PDF, EPUB and Kindle. Book excerpt: Laser-based optical spectroscopies are powerful and versatile techniques that are continuing to evolve and find new applications. This book presents reviews of recent progress in our understanding of the spectra and dynamical processes of optically excited states of condensed matter, focusing on the advances made possible by the application of laser-based optical spectroscopies. Reviews are given of the optical properties of crystalline and amorphous semiconducting materials and structures, the properties of defect centers in insulators, two-photon nonlinear processes in insulators, optical energy diffusion in inorganic materials, and relaxation in organic materials. The individual chapters emphasize the methodology common to the various investigations. The volume is designed to be suitable as an introduction to applied laser spectroscopy of solids, as well as providing an update on the status of the field.

Download or read book Laser Spectroscopy and its Applications written by Richard W. Solarz and published by CRC Press. This book was released on 1986-09-29 with total page 712 pages. Available in PDF, EPUB and Kindle. Book excerpt: This monograph offers detailed and easy-to-read descriptions of the main techniques of laser spectroscopy and its applications. It is useful to engineers, technical managers, nonlaser scientists who require an introduction to the field, graduate students, and laser spectroscopists.

Download or read book Laser based Mid infrared Sources and Applications written by Konstantin L. Vodopyanov and published by John Wiley & Sons. This book was released on 2020-06-30 with total page 320 pages. Available in PDF, EPUB and Kindle. Book excerpt: An important guide to the major techniques for generating coherent light in the mid-infrared region of the spectrum Laser-based Mid-infrared Sources and Applications gives a comprehensive overview of the existing methods for generating coherent light in the important yet difficult-to-reach mid-infrared region of the spectrum (2–20 μm) and their applications. The book describes major approaches for mid-infrared light generation including ion-doped solid-state lasers, fiber lasers, semiconductor lasers, and laser sources based on nonlinear optical frequency conversion, and reviews a range of applications: spectral recognition of molecules and trace gas sensing, biomedical and military applications, high-field physics and attoscience, and others. Every chapter starts with the fundamentals for a given technique that enables self-directed study, while extensive references help conduct deeper research. Laser-based Mid-infrared Sources and Applications provides up-to-date information on the state-of the art mid-infrared sources, discusses in detail the advancements made over the last two decades such as microresonators and interband cascade lasers, and explores novel approaches that are currently subjects of intense research such as supercontinuum and frequency combs generation. This important book: • Explains the fundamental principles and major techniques for coherent mid-infrared light generation • Discusses recent advancements and current cutting-edge research in the field • Highlights important biomedical, environmental, and military applications Written for researchers, academics, students, and engineers from different disciplines, the book helps navigate the rapidly expanding field of mid-infrared laser-based technologies.

Download or read book Advances in Spectroscopy for Lasers and Sensing written by Baldassare Di Bartolo and published by Springer Science & Business Media. This book was released on 2006-07-21 with total page 574 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume presents the Proceedings of "New Development in Optics and Related Fields," held in Italy in June, 2005. This meeting was organized by the International School of Atomic and Molecular Spectroscopy of the "Ettore Majorana" Center for Scientific Culture. The purpose of this Institute was to provide a comprehensive and coherent treatment of the new techniques and contemporary developments in optics and related fields.

Download or read book Laser Spectroscopy 2 written by Wolfgang Demtröder and published by Springer. This book was released on 2015-01-07 with total page 773 pages. Available in PDF, EPUB and Kindle. Book excerpt: Keeping abreast of the latest techniques and applications, this new edition of the standard reference and graduate text on laser spectroscopy has been completely revised and expanded. While the general concept is unchanged, the new edition features a broad array of new material, e.g., ultrafast lasers (atto- and femto-second lasers), coherent matter waves, Doppler-free Fourier spectroscopy, interference spectroscopy, quantum optics and gravitational waves and still more applications in chemical analysis, medical diagnostics, and engineering.

Download or read book Advances in Laser Spectroscopy written by F. T. Arecchi and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 500 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Applied Laser Spectroscopy written by Wolfgang Demtröder and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 495 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume contains the lectures and seminars presented at the NATO Advanced Study Institute on "Applied Laser Spectroscopy" the fourteenth course of the Europhysics School of Quantum Electronics, held under the supervision of the Quantum Electronics Division of the European Physical Society. The Institute was held at Centro "I Cappuccini", San Miniato, Tuscany, Italy, September 3-15,1989. The Europhysics School of Quantum Electronics was started in 1970 with the aim of providing instruction for young researchers and advanced students already engaged in the area of quantum electronics or wishing to switch to this area from a different background. Presently the school is under the direction of Professors F.T. Arecchi and M Inguscio, University of Florence and Prof. H. Walther University of Munich and has the headquarters at the National Institute of Optics (INO), Firenze, Italy. Each time the directors choose a subject of particular interest, alternating fundamental topics with technological ones, and ask colleagues specifically competent in a given area to take the scientific responsibility for that course.