Download or read book Spectral Domain Optical Coherence Tomography Using a Microchip Laser pumped Photonic Crystal Fiber Supercontinuum Source written by Qi Zhao and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Optical Coherence Tomography (OCT) is a well established biomedical imaging technique, which produces ultrahigh spatial resolution cross-sectional images of biological tissue in the range of a few millimeters. The axial resolution of OCT improves with a larger bandwidth optical source. Traditional OCT often uses a femtosecond laser as the broadband optical source. Recently, supercontinuum spectrum has been demonstrated by using the combination of femtosecond lasers and nonlinear effects of photonic crystal fiber. However, this source has fairly high cost. This thesis investigates OCT using a more cost effective source based on a microchip laser-pumped photonic crystal fiber. The Q-switched Nd:YAG microchip laser produces 0.6 ns duration pulses at 1064 nm with 8 mu-J of energy at a 6.6 kHz repetition rate. These pulses are sent through a photonic crystal fiber with a zero dispersion wavelength of 1040 nm. The generated supercontinuum pulses are coupled into a fiber-based spectral domain OCT system operating at a central wavelength of 800 nm. The axial scan rate is 6.6 kHz, where each scan is produced by a single supercontinuum pulse. Point spread function measurements show excellent resolution, but sensitivity is degraded by spectral fluctuations of individual supercontinuum pulses. Test images show less dynamic range compared to a Ti:Sapphire femtosecond laser based system. However, this supercontinuum source has potential for stroboscopic illumination in time-resolved low coherence interferometry.
Download or read book Supercontinuum Generated by Noise Like Pulses for Time Domain and Spectral Domain Optical Coherence Tomography written by 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 Optical Coherence Tomography written by Jianbing Xu and published by Open Dissertation Press. This book was released on 2017-01-27 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation, "Optical Coherence Tomography: From System Design to Spectroscopic Applications" by Jianbing, Xu, 徐鉴冰, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. Abstract: Optical coherence tomography (OCT), as a newly developed imaging modality, has attracted significant attention due to its capability to obtain the cross-sectional information of biological tissues in a non-invasive way, with resolution in the range of several micrometers. The third-generation swept source OCT (SS-OCT), is superior in the speed, imaging range and signal-to-noise ratio (SNR) compared with the previous time-domain OCT (TD-OCT) and spectral domain OCT (SD-OCT), and therefore forms our research focus. In this thesis, for the first time, I investigate the deployment of Fourier domain mode-locked (FDML) swept laser by utilizing the bismuth-based erbium doper fiber (Bi-EDF) with a sweeping bandwidth of 81nm achieved. Following, fiber Raman amplifier (FRA) is also investigated by employing multiple Raman pumps. The tuning range is 111.8nm, which is much larger than the previous reported Raman pumped FDML in the 1550nm region. Imaging was performed to validate the feasibility of the proposed schemes for the SS-OCT applications, respectively. In addition to the FDML swept laser cavity design, speckle noise reduction is also of great importance in OCT, which can significantly improve the visibility of the obtained OCT images. I demonstrate two different speckle reduction methods for OCT applications, which are superior in suppressing speckle noise and reserving the one-dimensional (1D) and two-dimensional (2D) signal information, respectively. Applying the proposed wavelet domain compounding (WDC) and contourlet shrinkage method to despeckle the OCT images, the visibility of the OCT images was significantly improved, with negligible edge preservation compromise. Spectroscopic information is also of interest to many researchers as it provides additional spectroscopic contrast, which on one hand, will improve the visualization of the images, and on the other hand, will enable the classification of different tissue types and help the process of discrimination between invasive and noninvasive tumors. Compared with our previous reported work about dual-band spectroscopic OCT based on optical parametric amplifier (OPA) to generate another idler band, which will be used as the second band for dual-band spectroscopic analysis, I further extend the dual-band spectroscopic OCT to the endoscopic applications, and investigate the dual-band FDML swept laser configuration based on a custom-designed dual-channel driver to synchronize the two different wavelength bands, centered at 1310 and 1550 nm, respectively. OCT Images for different bands are captured and post-processed by coding the spectral difference in different colors. In short, in this thesis, the investigations of OCT range from system design, speckle reduction to the spectroscopic applications. All these research efforts will extend the current FDML techniques for a wide range of SS-OCT applications. These schemes may be useful in OCT swept laser source build up, speckle noise reduction, and the extension of spectroscopic analysis. DOI: 10.5353/th_b5317037 Subjects: Optical coherence tomography
Download or read book Spectral Domain Optical Coherence Tomography written by and published by . This book was released on 2008 with total page 134 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Coherence Domain Optical Methods and Optical Coherence Tomography in Biomedicine written by and published by . This book was released on 2007 with total page 498 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book System Integration of Spectral Domain Optical Coherence Tomography with Virtual Detector Laser scanning Optical Resolution Photoacoustic Microscopy written by 李正綱 and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Optics Letters written by and published by . This book was released on 2008 with total page 760 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Optimization of the Control and Algorithm of the Spectral Domain Optical Coherence Tomography written by Hassan Wehbe and published by . This book was released on 2005 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Spectral domain Optical Coherence Tomography on a Silicon Chip written by and published by . This book was released on 2012 with total page 138 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Coherence Domain Optical Methods and Optical Coherence Tomography in Biomedicine X written by and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Functional Optical Coherence Tomography Based on Broadband Crystal Fiber Light Source written by 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 Enhanced Spectral Domain Optical Coherence Tomography for Pathological and Functional Studies written by Zhijia Yuan and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Laser Physics written by and published by . This book was released on 2004 with total page 518 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Supercontinuum Generation in Optical Fibers written by J. M. Dudley and published by Cambridge University Press. This book was released on 2010-04-01 with total page 419 pages. Available in PDF, EPUB and Kindle. Book excerpt: The optical fiber based supercontinuum source has recently become a significant scientific and commercial success, with applications ranging from frequency comb production to advanced medical imaging. This one-of-a-kind book explains the theory of fiber supercontinuum broadening, describes the diverse operational regimes and indicates principal areas of applications, making it a very important guide for researchers and graduate students. With contributions from major figures and groups who have pioneered research in this field, the book describes the historical development of the subject, provides a background to the associated nonlinear optical processes, treats the generation mechanisms from continuous wave to femtosecond pulse pump regimes and highlights the diverse applications. A full discussion of numerical methods and comprehensive computer code are also provided, enabling readers to confidently predict and model supercontinuum generation characteristics under realistic conditions.
Download or read book Recent Progress in Optical Fiber Research written by Moh Yasin and published by . This book was released on 2012 with total page 464 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents a comprehensive account of the recent progress in optical fiber research. It consists of four sections with 20 chapters covering the topics of nonlinear and polarisation effects in optical fibers, photonic crystal fibers and new applications for optical fibers. Section 1 reviews nonlinear effects in optical fibers in terms of theoretical analysis, experiments and applications. Section 2 presents polarization mode dispersion, chromatic dispersion and polarization dependent losses in optical fibers, fiber birefringence effects and spun fibers. Section 3 and 4 cover the topics of photonic crystal fibers and a new trend of optical fiber applications. Edited by three scientists with wide knowledge and experience in the field of fiber optics and photonics, the book brings together leading academics and practitioners in a comprehensive and incisive treatment of the subject. This is an essential point of reference for researchers working and teaching in optical fiber technologies, and for industrial users who need to be aware of current developments in optical fiber research areas.
Download or read book Encyclopedia of Laser Physics and Technology written by Rüdiger Paschotta and published by John Wiley & Sons. This book was released on 2008-12-03 with total page 857 pages. Available in PDF, EPUB and Kindle. Book excerpt: This authoritative two-volume encyclopedia (A-M, N-Z) helps to master the large variety of physical phenomena and technological aspects involved in laser technology and the wider field of photonics. Besides explaining in detail the physical principles and common techniques of laser operation, it also addresses such supplementary topics as ultrashort pulses, optical communications, optoelectronics, general optics, and quantum optics. References to selected scientific articles and textbooks aid readers in their further studies, and the cross-disciplinary approach makes this four-color encyclopedia of huge benefit to a wide audience in industry, government, and academic research.
Download or read book The Supercontinuum Laser Source written by Robert R. Alfano and published by Springer Science & Business Media. This book was released on 2006-02-14 with total page 552 pages. Available in PDF, EPUB and Kindle. Book excerpt: This new edition of a classic in the field has been expanded and enriched with new content and updated references. The book covers the fundamental principles and surveys research of current thinkers and experts in the field with updated references of the key breakthroughs over the past decade and a half.
