Download or read book Recent Results in Quantum Cascade Lasers and Applications written by Claire Gmachi and published by . This book was released on 2000 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent advances in quantum cascade (QC) lasers include widely tunable single-mode distributed feedback (DFB) lasers with high optical power at lamba approximately 4.6 micrometers. and single-mode DFB lasers at lamba approximately 16 micrometers based on new surface plasmons waveguides with dual-metal gratings. Single-mode and tunable QC-DFB lasers have successfully been used in many collaborations for various trace-gas sensing applications. Examples are the detection of stratospheric methane and nitrous oxide, the sub-ppbv detection of ammonia by cavity ring down spectroscopy, methane concentration and isotopic composition measurements. and the detection of complex molecules in open air by direct absorption spectroscopy. The versatility of band structure engineering enabled the design and realization of QC-lasers. which operate under both. positive and negative polarity displaying distinct characteristics in each polarity if an asymmetric structure is employed.
Download or read book Quantum Cascade Lasers written by Jérôme Faist and published by Oxford University Press. This book was released on 2013-03-14 with total page 321 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book describes the physics, fabrication technology, and applications of the quantum cascade laser.
Download or read book Quantum Cascade Lasers QCLs written by Joseph D. Bennett and published by Nova Science Publishers. This book was released on 2016 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Quantum cascade lasers (QCLs) are unipolar devices with lasing occurring through transitions between quantised energy levels within the conduction band. When compared to conventional lasers (e.g. gas, liquid or solid state lasers), these new optoelectronic devices present a fundamental advantage that resides in their ability to tailor the wavelength of the emitted light via the layer thickness rather than the band gap. This book discusses different types and applications of quantum cascade lasers.
Download or read book Spectroscopic Applications of Terahertz Quantum Cascade Lasers written by Tasmim Alam and published by Cuvillier Verlag. This book was released on 2020-10-29 with total page 132 pages. Available in PDF, EPUB and Kindle. Book excerpt: Quantum cascade lasers (QCLs) are attractive for high-resolution spectroscopy because they can provide high power and a narrow linewidth. They are particularly promising in the terahertz (THz) range since they can be used as local oscillators for heterodyne detection as well as transmitters for direct detection. However, THz QCL-based technologies are still under development and are limited by the lack of frequency tunability as well as the frequency and output power stability for free-running operation. In this dissertation, frequency tuning and linewidth of THz QCLs are studied in detail by using rotational spectroscopic features of molecular species. In molecular spectroscopy, the Doppler eff ect broadens the spectral lines of molecules in the gas phase at thermal equilibrium. Saturated absorption spectroscopy has been performed that allows for sub-Doppler resolution of the spectral features. One possible application is QCL frequency stabilization based on the Lamb dip. Since the tunability of the emission frequency is an essential requirement to use THz QCL for high-resolution spectroscopy, a new method has been developed that relies on near-infrared (NIR) optical excitation of the QCL rear-facet. A wide tuning range has been achieved by using this approach. The scheme is straightforward to implement, and the approach can be readily applied to a large class of THz QCLs. The frequency and output stability of the local oscillator has a direct impact on the performance and consistency of the heterodyne spectroscopy. A technique has been developed for a simultaneous stabilization of the frequency and output power by taking advantage of the frequency and power regulation by NIR excitation. The results presented in this thesis will enable the routine use of THz QCLs for spectroscopic applications in the near future.
Download or read book Mid Infrared and Terahertz Quantum Cascade Lasers written by Dan Botez and published by Cambridge University Press. This book was released on 2023-06-30 with total page 551 pages. Available in PDF, EPUB and Kindle. Book excerpt: A state-of-the-art overview of this rapidly expanding field, featuring fundamental theory, practical applications, and real-life examples.
Download or read book Mid infrared Quantum Cascade Lasers for Chaos Secure Communications written by Olivier Spitz and published by Springer Nature. This book was released on 2021-05-15 with total page 179 pages. Available in PDF, EPUB and Kindle. Book excerpt: The mid-infrared domain is a promising optical domain because it holds two transparency atmospheric windows, as well as the fingerprint of many chemical compounds. Quantum cascade lasers (QCLs) are one of the available sources in this domain and have already been proven useful for spectroscopic applications and free-space communications. This thesis demonstrates how to implement a private free-space communication relying on mid-infrared optical chaos and this requires an accurate cartography of non-linear phenomena in quantum cascade lasers. This private transmission is made possible by the chaos synchronization of two twin QCLs. Chaos in QCLs can be generated under optical injection or external optical feedback. Depending on the parameters of the optical feedback, QCLs can exhibit several non-linear phenomena in addition to chaos. Similarities exist between QCLs and laser diodes when the chaotic dropouts are synchronized with an external modulation, and this effect is known as the entrainment phenomenon. With a cross-polarization reinjection technique, QCLs can generate all-optical square-waves. Eventually, it is possible to trigger optical extreme events in QCLs with tilted optical feedback. All these experimental results allow a better understanding of the non-linear dynamics of QCLs and will extend the potential applications of this kind of semiconductor lasers.
Download or read book Quantum Cascade Lasers and Optical Metamaterials written by Matthew Escarra and published by LAP Lambert Academic Publishing. This book was released on 2013-01 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt: Quantum cascade (QC) lasers have application in areas such as medical diagnostics and homeland security. Optical metamaterials have novel interactions with light and potential application for sub-wavelength imaging and optical cloaking. This work first explores new approaches to designing QC lasers. High performance QC lasers are described with a voltage defect of only 19 meV, resulting in record voltage efficiency. Lasers with ultra-strong coupling attain 50% wall-plug efficiency. The thermoelectric effect is measured for the first time within QC lasers, informing further performance enhancements. This work then describes two efforts to improve mid-IR metamaterials. Negative refraction bandwidth and dispersion properties are improved through the use of multiple-metamaterial stacks. QC gain regions are added to these metamaterials to reduce their absorption loss. Finally, QC lasers are developed for trace gas sensing of CO2 isotopes, and a techno-economic model is used to value improved CO2 isotope-based sequestration leakage monitoring. QC laser applications in non-invasive tissue measurements, inter-planetary sensors, C60 spectroscopy, and IR countermeasures are also examined.
Download or read book Applications for Quantum Cascade Lasers and Detectors in Mid infrared High resolution Heterodyne Astronomy written by and published by . This book was released on with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Quantum cascade (QC) structures, for both emitting and detecting mid-infrared radiation, are powerful devices for spectroscopy. QC lasers (QCLs), which have been built for nearly 15 years, already play the leading role in certain wavelength regions. QC detectors (QCDs) are a fairly new development, which has been evolving from the QCL research. In high-resolution heterodyne spectrometers for astronomy, such as the Cologne tuneable heterodyne infrared spectrometer (THIS), QC devices help to open new windows to space as discussed in this paper. We will briefly review the use of QC devices in THIS, show recent results in measuring planetary atmospheric dynamics and give an outlook to astronomical goals for the future.
Download or read book Quantum Cascade Lasers written by Jérôme Faist and published by OUP Oxford. This book was released on 2013-03-14 with total page 321 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides an introduction to quantum cascade lasers, including the basic underlying models used to describe the device. It aims at giving a synthetic view of the topic including the aspects of the physics, the technology, and the use of the device. It should also provide a guide for the application engineer to use this device in systems. The book is based on lecture notes of a class given for Masters and beginning PhD students. The idea is to provide an introduction to the new and exciting developments that intersubband transitions have brought to the use of the mid-infrared and terahertz region of the electromagnetic spectrum. The book provides an introductory part to each topic so that it can be used in a self-contained way, while references to the literature will allow deeper studies for further research.
Download or read book Advances in Semiconductor Lasers and Applications to Optoelectronics written by Mitra Dutta and published by World Scientific. This book was released on 2000 with total page 458 pages. Available in PDF, EPUB and Kindle. Book excerpt: Foreword by Charles H Townes This volume includes highlights of the theories underlying the essential phenomena occurring in novel semiconductor lasers as well as the principles of operation of selected heterostructure lasers. To understand scattering processes in heterostructure lasers and related optoelectronic devices, it is essential to consider the role of dimensional confinement of charge carriers as well as acoustical and optical phonons in quantum structures. Indeed, it is important to consider the confinement of both phonons and carriers in the design and modeling of novel semiconductor lasers such as the tunnel injection laser, quantum well intersubband lasers, and quantum dot lasers. The full exploitation of dimensional confinement leads to the exciting new capability of scattering time engineering in novel semiconductor lasers.As a result of continuing advances in techniques for growing quantum heterostructures, recent developments are likely to be followed in coming years by many more advances in semiconductor lasers and optoelectronics. As our understanding of these devices and the ability to fabricate them grow, so does our need for more sophisticated theories and simulation methods bridging the gap between quantum and classical transport.
Download or read book Solid State Mid Infrared Laser Sources written by Irina T. Sorokina and published by Springer Science & Business Media. This book was released on 2003-07-10 with total page 600 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book describes the most advanced techniques for generating coherent light in the mid-infrared region of the spectrum. These techniques represent diverse areas of photonics and include heterojunction semiconductor lasers, quantum cascade lasers, tunable crystalline lasers, fiber lasers, Raman lasers, and optical parametric laser sources. Offering authoritative reviews by internationally recognized experts, the book provides a wealth of information on the essential principles and methods of the generation of coherent mid-infrared light and on some of its applications. The instructive nature of the book makes it an excellent text for physicists and practicing engineers who want to use mid-infrared laser sources in spectroscopy, medicine, remote sensing and other fields, and for researchers in various disciplines requiring a broad introduction to the subject.
Download or read book Engineering Light written by and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Quantum cascade lasers are ideal for environmental sensing and medical diagnostic applications. Gmachl discusses how these lasers work, and their applications, including their use as chemical trace gas sensors. As examples of these applications, she briefly presents results from her field campaign at the Beijing Olympics, and ongoing campaigns in Texas, Maryland, and Ghana.
Download or read book Nonlinear Laser Dynamics written by Kathy Lüdge and published by John Wiley & Sons. This book was released on 2012-01-17 with total page 412 pages. Available in PDF, EPUB and Kindle. Book excerpt: A distinctive discussion of the nonlinear dynamical phenomena of semiconductor lasers. The book combines recent results of quantum dot laser modeling with mathematical details and an analytic understanding of nonlinear phenomena in semiconductor lasers and points out possible applications of lasers in cryptography and chaos control. This interdisciplinary approach makes it a unique and powerful source of knowledge for anyone intending to contribute to this field of research. By presenting both experimental and theoretical results, the distinguished authors consider solitary lasers with nano-structured material, as well as integrated devices with complex feedback sections. In so doing, they address such topics as the bifurcation theory of systems with time delay, analysis of chaotic dynamics, and the modeling of quantum transport. They also address chaos-based cryptography as an example of the technical application of highly nonlinear laser systems.
Download or read book Nonlinear Photonics in Mid infrared Quantum Cascade Lasers written by Louise Jumpertz and published by Springer. This book was released on 2017-08-31 with total page 152 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis presents the first comprehensive analysis of quantum cascade laser nonlinear dynamics and includes the first observation of a temporal chaotic behavior in quantum cascade lasers. It also provides the first analysis of optical instabilities in the mid-infrared range. Mid-infrared quantum cascade lasers are unipolar semiconductor lasers, which have become widely used in applications such as gas spectroscopy, free-space communications or optical countermeasures. Applying external perturbations such as optical feedback or optical injection leads to a strong modification of the quantum cascade laser properties. Optical feedback impacts the static properties of mid-infrared Fabry–Perot and distributed feedback quantum cascade lasers, inducing power increase; threshold reduction; modification of the optical spectrum, which can become either single- or multimode; and enhanced beam quality in broad-area transverse multimode lasers. It also leads to a different dynamical behavior, and a quantum cascade laser subject to optical feedback can oscillate periodically or even become chaotic. A quantum cascade laser under external control could therefore be a source with enhanced properties for the usual mid-infrared applications, but could also address new applications such as tunable photonic oscillators, extreme events generators, chaotic Light Detection and Ranging (LIDAR), chaos-based secured communications or unpredictable countermeasures.
Download or read book Polymer Surface Characterization written by Luigia Sabbatini and published by Walter de Gruyter GmbH & Co KG. This book was released on 2022-01-19 with total page 527 pages. Available in PDF, EPUB and Kindle. Book excerpt: This fully updated edition provides a broad approach to the surface analysis of polymers being of high technological interest. Modern analytical techniques, potential applications and recent advances in instrumental apparatus are discussed. The self-consistent chapters are devoted to spectroscopic and microscopic techniques which represent powerful tools for the characterization of morphology and chemical, physical, mechanical properties of polymer surfaces, interfaces, and thin fi lms. Selection of techniques which can properly address very shallow depth of surfaces, spanning from few angstroms to tens of nanometers Interaction of polymer surfaces with their surroundings is pointed out as a critical issue for specifi c applications
Download or read book Terahertz Spectroscopy written by Jamal Uddin and published by BoD – Books on Demand. This book was released on 2017-03-13 with total page 320 pages. Available in PDF, EPUB and Kindle. Book excerpt: The terahertz regime of the electromagnetic spectrum was largely unexplored due to the lack of technology needed to generate and detect the radiation. However, in the last couple of decades, there has been a dramatic increase in tools needed to harness the radiation. This remarkable progress made in the development of terahertz sources, components, and detectors has resulted in an ever-increasing inquisitiveness of the applications of terahertz technology in a wide range of fields including medicine, pharmaceuticals, security, sensing, and quality assurance. This book, Terahertz Spectroscopy - A Cutting Edge Technology, presents an overview of the recent advances in terahertz technology and their application in a vast array of fields. The scientists and students are encouraged to read and share the content of this volume. The book also provides a good starting point for researchers who are new to the terahertz regime. The various chapters of the book have been written by renowned scientists in different parts of the world who are at the forefront of terahertz research fields. It is our (InTech publisher, editor, and authors) hope that this book will enhance knowledge and stimulate more interest and future research in terahertz technology.
Download or read book Intersubband Transitions in Quantum Wells Physics and Devices written by Sheng S. Li and published by Springer Science & Business Media. This book was released on 2013-11-27 with total page 221 pages. Available in PDF, EPUB and Kindle. Book excerpt: The International Workshop on "Intersubband Transitions in Quantum Wells:: Physics and Applications," was held at National Cheng Kung University, in Tainan, Taiwan, December 15-18, 1997. The objective of the Workshop is to facilitate the presentation and discussion of the recent results in theoretical, experimental, and applied aspects of intersubband transitions in quantum wells and dots. The program followed the tradition initiated at the 1991 conference in Cargese-France, the 1993 conference in Whistler, B. C. Canada, and the 1995 conference in Kibbutz Ginosar, Israel. Intersubband transitions in quantum wells and quantum dots have attracted considerable attention in recent years, mainly due to the promise of various applications in the mid- and far-infrared regions (2-30 J. lm). Over 40 invited and contributed papers were presented in this four-day workshop, with topics covered most aspects of the intersubband transition phenomena including: the basic intersubband transition processes, multiquantum well infrared photodetector (QWIP) physics, large format (640x480) GaAs QWIP (with 9. 0 J. lffi cutoff) focal plane arrays (FPAs) for IR imaging camera applications, infrared modulation, intersubband emission including mid- and long- wavelength quantum cascade (QC) lasers such as short (A. "" 3. 4 J. lm) and long (A. "" 11. 5 J. lm) wavelength room temperature QC lasers, quantum fountain intersubband laser at 15. 5 J. lm wavelength in GaAs/AIGaAs quantum well, harmonic generation and nonlinear effects, ultra-fast phenomena such as terahertz (THz) intersubband emission and detection. The book divides into five Chapters.
