Download or read book An Introduction to Self mixing Interferometry with an Application to Vibrometry written by Matthew L. O'Donnell and published by . This book was released on 2008 with total page 112 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Laser Doppler Vibrometry written by Enrico Primo Tomasini and published by Springer Nature. This book was released on 2020-06-29 with total page 173 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a continuous learning tool for experienced technical staff facing laser vibrometry technology for the first time. The book covers both theoretical aspects and practical applications of laser Doppler vibrometry, and is accompanied by a multimedia presentation that allows the audience to browse the content and come as close as possible to performing real experiments. After a brief introduction, Chapter 2 presents supporting theory, providing general information on light sources, light scattering and interference for a better understanding of the rest of the book. Chapter 3 examines the theory of laser vibrometers, explaining interferometers from an optical perspective and in terms of the related electronics. It also addresses options like tracking filters and different signal demodulation strategies, since these have a significant impact on the practical use of vibrometers. Chapter 4 explores the configurations that are encountered in today’s instrumentation, with a focus on providing practical suggestions on the use of laser vibrometers. Lastly, Chapter 5 investigates metrology for vibration and shock measurements using laser interferometry, and analyses the uncertainty of laser vibrometers in depth.
Download or read book Self mixing Interferometry for Absolute Distance Measurement written by Mengkoung Veng (docteur en photonique).) and published by . This book was released on 2020 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Self-mixing Interferometry has been studied extensively in the last five decades in various sensing applications. Sensors under the SMI technique have the laser diode as the light source, the interferometer, and the detector. The light from the laser diode propagates towards a distant target where it is partially reflected or back-scattered before being re-injected into the active cavity of the laser. When the laser diode experiences the external optical feedback, the reflected light imprinted with information from the distant target or from the external cavity medium induces perturbation to the operating parameters of the laser. For SMI measurement sensors such as harmonic motion and absolute distance applications, the fringe counting method is basically used to determine the target's displacement and distance respectively. Two different approaches to modelling the SMI phenomenon have been developed: the three-mirror cavity and the perturbation of the rate equation. The single equation that describes the phase condition imposed by the optical feedback is usually referred to as the excess phase equation. One of the most important and most useful parameters in the excess phase equation is the feedback parameter C as it can be used to qualitatively categorize the regime of the laser under optical feedback. When the feedback level C 1, the laser behaviour is stable. On the other hand, when the feedback level C 1, more complex phenomena are observed such as hysteresis effect, presence of multiple emission frequencies (including the unstable frequencies), apparent splitting of the emission line due to mode hopping and fringe disappearance phenomenon. The fringes disappearance phenomenon in the self-mixing interferometry occurs whenever the external round-trip phase at free-running state is modulated by either external modulation such as external cavity length changes or internal modulation when the laser injection current is modulated with a high back-scattered light power. This phenomenon has been observed by many authors for harmonic motion or vibration application and more recently in the case of the absolute distance measurement scheme when the laser injection current is modulated in the triangle waveform. This phenomenon is highly dependent on the feedback parameter C and it is described in detail based on the coupled cavity model. The primary cause for fringes disappearance is demonstrated to be the expansion of the excess phase equation stable solutions range with the increment of the parameter C, thus reducing the number of stable solutions for a given phase stimulus. This new approach in the modelling of the fringe disappearance phenomenon allows determination of the C values for which a pair of fringes are expected to disappear and as a consequence correlates the number of missing fringes to the value of C. This approach is validated both by a behavioural model of the laser under optical feedback and by a series of measurements in the SMI absolute distance configuration.
Download or read book Adaptive Self mixing Interferometry for Metrology Applications written by Reza Atashkhooei and published by . This book was released on 2014 with total page 149 pages. Available in PDF, EPUB and Kindle. Book excerpt: Among the laser based techniques proposed for metrology applications, classical interferometers offer the highest precision measurements. However, the cost of some of the elements involved and the number of optical components used in the setup complicates using them in several industrial applications. Apart from cost, the complexities due to optical alignment and the required quality of the environmental conditions can be quite restrictive for those systems. Within the category of optical interferometers, optical feedback interferometry (OFI), also called self-mixing interferometry (SMI) has the potential to overcome some of the complexities of classical interferometry. It is compact in size, cost effective, robust, self-aligned, and it doesn't require a large number of optical components in the experimental configuration. In OFI, a portion of the emitted laser beam re-enters to the laser cavity after backreflection from the target, causing the wavelength of the laser to change, modifying the power spectrum and consequently the emitted output power, which can be detected for measurement purposes. Thus, the laser operates simultaneously as the light source, the light detector, and as the ultra-sensitive coherent sensor for optical path changes. The present PhD pursued improving the performance of OFI-based sensors using a novel and compact optical system. A solution using an adaptive optical element in the form of a voltage programmable liquid lens was proposed for automated focus adjustments. The amount of backreflected light re-entering the laser cavity could be controlled, and the laser feedback level was adjusted to the best condition in different situations, enabling the power signal to be adjusted to the best possible conditions for measurement. Feedback control enabled the proposal of a novel solution called differential OFI, which improved the measurement resolution down to the nanometre order, even if the displacements were below half-wavelength of the laser, for first time in OFI sensors. Another relevant part of the PhD was devoted to the analysis of speckle-affected optical power signals in feedback interferometers. Speckle effect appears when the displacements of the target are large, and introduces an undesired modulation of the amplitude of the signal. After an analysis of the speckle-affected signal and the main factors contributing to it, two novel solutions were proposed for the control of speckle noise. The adaptive optical head developed previously was used in a real time setup to control the presence of speckle effect, by tracking the signal to noise ratio of the emitted power, and modifying the spot size on the target when required using a feedback loop. Besides, a sensor diversity solution was proposed to enable enhancements in signal detection in fast targets, when real time control could not be applied. Finally, two industrial applications of the technique with the presence of different levels of speckle noise have been presented. A complete measurement methodology for the control of motor shaft runout in permanent magnet electrical motors, enabling complete monitoring of the displacement of the shaft has been developed and implemented in practice. Results here are validated with those obtained using a commercial laser Doppler vibrometer, an equipment with a much higher cost. A second application in the monitoring the displacement of polymer-reinforced beams used in civil engineering under dynamic loading was also demonstrated. Results here are validated using a conventional contact probe (a Linear Vertical Differential Transducer, LVDT). Both applications show that with controlled speckle features OFI performs adequately in industrial environments as a non-contact proximity probe with resolution limited by the constraints defined by the setup.
Download or read book Self mixing Interferometry with Vertical cavity Surface emitting Lasers written by John Tucker and published by . This book was released on 2010-02 with total page 280 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Unlocking Dynamical Diversity written by Deborah M. Kane and published by John Wiley & Sons. This book was released on 2005-11-01 with total page 356 pages. Available in PDF, EPUB and Kindle. Book excerpt: Applications of semiconductor lasers with optical feedback systems are driving rapid developments in theoretical and experimental research. The very broad wavelength-gain-bandwidth of semiconductor lasers combined with frequency-filtered, strong optical feedback create the tunable, single frequency laser systems utilised in telecommunications, environmental sensing, measurement and control. Those with weak to moderate optical feedback lead to the chaotic semiconductor lasers of private communication. This resource illustrates the diversity of dynamic laser states and the technological applications thereof, presenting a timely synthesis of current findings, and providing the roadmap for exploiting their future potential. * Provides theory-based explanations underpinned by a vast range of experimental studies on optical feedback, including conventional, phase conjugate and frequency- filtered feedback in standard, commercial and single-stripe semiconductor lasers * Includes the classic Lang-Kobayashi equation model, through to more recent theory, with new developments in techniques for solving delay differential equations and bifurcation analysis * Explores developments in self-mixing interferometry to produce sub-nanometre sensitivity in path-length measurements * Reviews tunable single frequency semiconductor lasers and systems and their diverse range of applications in sensing and optical communications * Emphasises the importance of synchronised chaotic semiconductor lasers using optical feedback and private communications systems Unlocking Dynamical Diversity illustrates all theory using real world examples gleaned from international cutting-edge research. Such an approach appeals to industry professionals working in semiconductor lasers, laser physics and laser applications and is essential reading for researchers and postgraduates in these fields.
Download or read book Self mixing Interferometry and Its Applications in Noninvasive Pulse Detection written by Jukka Hast and published by . This book was released on 2003 with total page 72 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Photonic Instrumentation written by Silvano Donati and published by CRC Press. This book was released on 2023-06-27 with total page 521 pages. Available in PDF, EPUB and Kindle. Book excerpt: Photonic Instrumentation: Sensing and Measuring with Lasers is designed as a source for university-level courses covering the essentials of laser-based instrumentation, and as a useful reference for working engineers. Photonic instruments have very desirable features like non-contact operation and unparalleled sensitivity. They have quickly become a big industrial success, passing unaffected through the bubble years and, not any less important, well-established methods in measurement science. This book offers coverage of the most proven instruments, with a balanced treatment of the optical and electronic aspects involved. It also attempts to present the basic principles, develop the guidelines of design and evaluate the ultimate limits of performances set by noise. The instruments surveyed include: alignment instruments, such as wire diameter and particle size analyzers, telemeters, laser interferometers and self-mixing interferometers, and speckle pattern instruments, laser doppler velocimeters, gyroscopes, optical fiber sensors and quantum sensing. A few appendices offer convenient reference material for key principles on lasers, optical interferometers, propagation, scattering and diffraction.
Download or read book Improving the Performance of Optical Feedback Self mixing Interferometry for Vibration Measurement written by Yi Zhang and published by . This book was released on 2006 with total page 230 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Self mixing Interferometry with a Laser Diode for Light Scattering Studies written by Christian Maurice Zakian Dominguez and published by . This book was released on 2006 with total page 258 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Issues in Electronic Circuits Devices and Materials 2011 Edition written by and published by ScholarlyEditions. This book was released on 2012-01-09 with total page 3775 pages. Available in PDF, EPUB and Kindle. Book excerpt: Issues in Electronic Circuits, Devices, and Materials: 2011 Edition is a ScholarlyEditions™ eBook that delivers timely, authoritative, and comprehensive information about Electronic Circuits, Devices, and Materials. The editors have built Issues in Electronic Circuits, Devices, and Materials: 2011 Edition on the vast information databases of ScholarlyNews.™ You can expect the information about Electronic Circuits, Devices, and Materials in this eBook to be deeper than what you can access anywhere else, as well as consistently reliable, authoritative, informed, and relevant. The content of Issues in Electronic Circuits, Devices, and Materials: 2011 Edition has been produced by the world’s leading scientists, engineers, analysts, research institutions, and companies. All of the content is from peer-reviewed sources, and all of it is written, assembled, and edited by the editors at ScholarlyEditions™ and available exclusively from us. You now have a source you can cite with authority, confidence, and credibility. More information is available at http://www.ScholarlyEditions.com/.
Download or read book Electro Optical Instrumentation written by Silvano Donati and published by Pearson Education. This book was released on 2004-04-09 with total page 636 pages. Available in PDF, EPUB and Kindle. Book excerpt: The complete, practical sourcebook for laser sensing and measurement This is a systematic, up-to-date guide to laser instrumentation for sensing and measurement in contemporary scientific, industrial, automotive and avionics applications. Dr. Silvano Donati presents clear design rules and useful hints for practical implementation of a wide variety of laser instruments. For each type of instrument, the author outlines basic principles, physical limitations, reasonable performance expectations, optical design issues, and electronic signal handling--illustrated with block schemes. Coverage includes: Interferometers for sub-micrometer displacement measurements Nanometer vibrometers and structural integrity testing Doppler velocimeters for anemometry of fluids Range finders and anti-collision systems Non-contact wire-diameter and particle-diameter sizing Alignment and level meter apparatuses Ring laser and optical fiber gyroscopes Optical fiber sensors Thorough and accessible, Electro-Optical Instrumentation offers balanced coverage of both optical and electronic issues and challenges. It will give working electronic engineers and scientists the knowledge they need to design virtually any electro-optical instrumentation system. PRENTICE HALL Upper Saddle River, NJ 07458 www.phptr.com
Download or read book An Introduction to Interferometry written by S. Tolansky and published by . This book was released on 1955 with total page 223 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Introduction to Interferometry written by Samuel Tolansky and published by . This book was released on 1955 with total page 223 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book An Introduction to Interferometry written by S. Tolansky and published by . This book was released on 2003-01-01 with total page 223 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Basics of Interferometry written by P. Hariharan and published by Academic Press. This book was released on 2012-12-02 with total page 232 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is for those who have some knowledge of optics, but little or no previous experience in interferometry. Accordingly, the carefully designed presentation helps readers easily find and assimilate the interferometric techniques they need for precision measurements. Mathematics is held to a minimum, and the topics covered are also summarized in capsule overviews at the beginning and end of each chapter. Each chapter also contains a set of worked problems that give a feel for numbers.The first five chapters present a clear tutorial review of fundamentals. Chapters six and seven discuss the types of lasers and photodetectors used in interferometry. The next eight chapters describe key applications of interferometry: measurements of length, optical testing, studies of refractive index fields, interference microscopy, holographic and speckle interferometry, interferometric sensors, interference spectroscopy, and Fourier-transform spectroscopy. The final chapter offers suggestions on choosing and setting up an interferometer.
Download or read book Semiconductor Lasers written by Junji Ohtsubo and published by Springer. This book was released on 2017-05-03 with total page 679 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book describes the fascinating recent advances made concerning the chaos, stability and instability of semiconductor lasers, and discusses their applications and future prospects in detail. It emphasizes the dynamics in semiconductor lasers by optical and electronic feedback, optical injection, and injection current modulation. Applications of semiconductor laser chaos, control and noise, and semiconductor lasers are also demonstrated. Semiconductor lasers with new structures, such as vertical-cavity surface-emitting lasers and broad-area semiconductor lasers, are intriguing and promising devices. Current topics include fast physical number generation using chaotic semiconductor lasers for secure communication, development of chaos, quantum-dot semiconductor lasers and quantum-cascade semiconductor lasers, and vertical-cavity surface-emitting lasers. This fourth edition has been significantly expanded to reflect the latest developments. The fundamental theory of laser chaos and the chaotic dynamics in semiconductor lasers are discussed, but also for example the method of self-mixing interferometry in quantum-cascade lasers, which is indispensable in practical applications. Further, this edition covers chaos synchronization between two lasers and the application to secure optical communications. Another new topic is the consistency and synchronization property of many coupled semiconductor lasers in connection with the analogy of the dynamics between synaptic neurons and chaotic semiconductor lasers, which are compatible nonlinear dynamic elements. In particular, zero-lag synchronization between distant neurons plays a crucial role for information processing in the brain. Lastly, the book presents an application of the consistency and synchronization property in chaotic semiconductor lasers, namely a type of neuro-inspired information processing referred to as reservoir computing.
