Download or read book Development of Diode End pumped Nd YLF Lasers at 1314 Nm for High Power Operation written by Roelf Cornelis Botha and published by . This book was released on 2016 with total page 76 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Neurophotonics and Biomedical Spectroscopy written by Robert R. Alfano and published by William Andrew. This book was released on 2018-11-22 with total page 612 pages. Available in PDF, EPUB and Kindle. Book excerpt: Neurophotonics and Biomedical Spectroscopy addresses the novel state-of-the-art work in non-invasive optical spectroscopic methods that detect the onset and progression of diseases and other conditions, including pre-malignancy, cancer, Alzheimer's disease, tissue and cell response to therapeutic intervention, unintended injury and laser energy deposition. The book then highlights research in neurophotonics that investigates single and multi-photon excitation optical signatures of normal/diseased nerve tissues and in the brain, providing a better understanding of the underlying biochemical and structural changes of tissues and cells that are responsible for the observed spectroscopic signatures. Topics cover a wide array of well-established UV, visible, NIR and IR optical and spectroscopic techniques and novel approaches to diagnose tissue changes, including: label free in vivo and ex vivo fluorescence spectroscopy, Stoke shift spectroscopy, spectral imaging, Resonance Raman spectroscopy, multiphoton two Photon excitation, and more. - Provides an overview of the spectroscopic properties of tissue and tissue-light interaction, describing techniques to exploit these properties in imaging - Explores the potential and significance of molecule-specific imaging and its capacity to reveal vital new information on nanoscale structures - Offers a concise overview of different spectroscopic methods and their potential benefits for solving diagnostic and therapeutic problems
Download or read book Diode pumped Nd YLF lasers for high power operation written by Graham John Friel and published by . This book was released on 1998 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Development of a Frequency Doubled High Powered Laser Diode End pumped Nd YVO4 LBO Laser written by Aaron Maxwell Barr and published by . This book was released on 2003 with total page 624 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book 888 nm pumping of Nd YVO4 for high power TEM00 lasers written by Louis McDonagh and published by Cuvillier Verlag. This book was released on 2011-02-28 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt: For the last decade, neodymium-doped orthovanadate has established itself as the active material of choice for commercial solid-state lasers emitting in the 1 µm range, with output powers from several hundred milliwatts to a few tens of watts, in continuous-wave, short nanosecond Q-switched, or picosecond modelocked pulsed regimes. Its main advantages over other Nd-doped hosts such as YAG are a large stimulated-emission cross section leading to a high gain, a strong pump absorption allowing the efficient mode-matching of tightly-focused pump light, and a natural birefringence resulting in a continuously polarized output. The main drawbacks, however, are rather poor mechanical characteristics and strong thermal lensing, effectively limiting the maximum applicable pump power before excessively strong and aberrated thermal lensing prevents an efficient operation in a diffraction-limited beam, and ultimately the crystal’s fracture. Put aside the power limitation, the association of vanadate with diode end pumping allows for the realization of highly efficient and reliable laser sources based on well-known technologies, which provides an advantage in terms of manufacturability and cost-effectiveness over other high-potential technologies such as disks and fibers. This thesis introduces a novel pumping technique for Nd:YVO4 that allows for the realization of significantly higher-power laser sources with a high optical-to-optical efficiency and diffraction-limited beam quality, while keeping the benefits of a well-established technology. It consists in pumping at a wavelength of 888 nm instead of the classic 808 nm, providing a low and isotropic absorption, which results in a smooth distribution of the absorbed pump light in long crystals, effectively limiting the deleterious effects of high inversion density such as crystal end-facet bulging, high crystal temperature, aberrated thermal lensing, and upconversion. After presenting vanadate’s spectroscopic and physical characteristics, a complete analysis of the heatgenerating effects is performed, allowing for side-by-side simulations of the thermal effects in practical 808 nm and 888 nm pumped systems, and for an evaluation of their respective thermal lensing behaviors. Continuous-wave operation was thoroughly investigated, first in a multi-transversal mode oscillator to assess the maximum optical efficiency with optimum pump-mode matching and the thermal lensing characteristics. A TEM00 resonator was then developed with a single crystal and one pump diode, providing 60 W of output power with an optical efficiency of 55% and a beam quality of M2 = 1.05. This resonator was symmetrically replicated to form a periodic resonator, providing 120 W of output with the same optical efficiency and beam quality. This two-crystal configuration was then modified to an oscillator-amplifier configuration, providing a single-pass extraction efficiency of 53% and a total oscillator-amplifier output of 117 W without any beam-quality degradation. Intracavity doubling of the one and two-crystal configurations was achieved by inserting a non-critically phase-matched LiB5O3 (LBO) non-linear crystal in the resonator, providing up to 62 W of diffraction-limited green light at 532 nm with low-noise characteristics thanks to a large number of oscillating modes, thus limiting the effects of the “green problem”. A strong industrial interest resides in Q-switched lasers emitting nanosecond pulses, particularly with a high average power, high pulse repetition rate, and pulse durations of a few to several tens of nanoseconds. Achieving high-frequency and short-pulse operation both require a high gain, which explains the domination of Nd:YVO4 over lower-gain materials such as Nd:YAG or Yb:YAG. Thus, an acousto-optically Q-switched oscillator was demonstrated with 50 W output power and 28 ns pulse duration at 50 kHz. Pulse duration, however, is inversely proportional to the pulse energy, so that an increase in repetition rate inevitably results in an almost linear increase in pulse width. A cavity-dumped Q-switched oscillator was built to circumvent this limitation, the pulse length being defined by the cavity roundtrip time and the electro-optic cell switching time. It provided a constant pulse duration of 6 ns up to a repetition rate of 100 kHz and a maximum output power of 47 W. Such short pulse durations are normally available with output powers of a few watts from Q-switched lasers, and conversely Q-switched lasers of similarly high output power deliver pulses of several tens to over 100 ns in duration. There exists another strong interest in high average power quasi-cw picosecond sources, which allow for the efficient generation of green and UV radiation, or even red-green-blue for laser video projection. Passive mode locking with a semiconductor saturable absorber mirror (SESAM) is the preferred technique employed for the stable and self-starting generation of picosecond pulse trains, yet a high gain is necessary for achieving high repetition rates while avoiding the Q-switched mode-locking regime. Thus SESAM mode locking was applied to an 888 nm pumped oscillator, achieving 57 W of output power at a repetition-rate of 110 MHz and a pulse duration of 33 ps. Its output was efficiently amplified in a single pass up to 111 W without any beam quality, temporal, or spectral degradation. The high peak power of 30 kW allowed for the generation of 87 W of second harmonic at 532 nm with an efficiency of 80%, and 35 W of 355 nm third harmonic with a conversion efficiency of 33% in LBO crystals. The wide range of high-power systems demonstrated in this work illustrate the benefits of the optimized pumping of Nd:YVO4 at 888 nm, maintaining its highly-desirable characteristics such as a high gain and a polarized output while extending its power capabilities far beyond regular 808 nm pumped systems. This improvement should allow Nd:YVO4 systems to compete with high-power technologies such as disks and fibers, which often struggle in the generation of short pulses because of their low gain and strong non-linear effects, respectively.
Download or read book Efficient CW Nd YLF Laser In band Diode pumped at 908 Nm and Its Thermal Lensing written by Zohreh Sedaghati and published by . This book was released on 2019 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Diode-pumped solid-state lasers are highly recommended for a variety of industrial and scientific applications as they can offer high efficiency and excellent beam quality. However, power scaling of these lasers is a challenging task. The main limitation in power scaling of famous neodymium doped lasers such as Nd:YVO4 is the thermal lensing effect. Thermal lensing degrades the output beam quality and in extreme cases can result in crystal fracture. One potential solution to this problem is to reduce the induced heat load inside the gain media by decreasing the quantum defect. This was demonstrated successfully for the Nd:YVO4 laser by pumping the laser at a long wavelength of 914 nm instead of the traditional pumping at 808 nm wavelength. Among the Nd-doped crystals operating in the near infrared range, the crystal of yttrium lithium fluoride (Nd:YLF) is another interesting gain medium as it has the benefits of natural birefringence (can generate naturally polarized laser beam), negative dn/dT (reduces thermal effects) and long upper level lifetime (in favor of Q-switched operation). In this work we used a long wavelength pumping approach and for the first time examined the performance of a continuous-wave Nd:YLF laser at 1047 nm under 908 nm diode pumping. This pumping wavelength reduced the quantum defect by 50% as compared to the conventional 808 nm pumping. The laser produced an output power of 850 mW at 1047 nm with excellent beam quality and 625 mW at 1053 nm. The slope efficiency was ~73.9% and 46% for 1047 and 1053 nm, respectively. Therefore, a considerable power scaling is possible for Nd:YLF crystals owing to the strongly reduced quantum defect and, hence, thermal lensing.
Download or read book Introduction to Laser Diode pumped Solid State Lasers written by Richard Scheps and published by SPIE-International Society for Optical Engineering. This book was released on 2002 with total page 122 pages. Available in PDF, EPUB and Kindle. Book excerpt: This text covers a wide range of material, from the basics of laser resonators to advanced topics in laser diode pumping. The subject matter is presented in descriptive terms that are understandable by the technical professional who does not have a strong foundation in fundamental laser topics.
Download or read book Diode Pumping of Average power Solid State Lasers written by Georg F. Albrecht and published by SPIE-International Society for Optical Engineering. This book was released on 1993 with total page 192 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book High Power Operation of the In band Diode pumped Nd GdVO4 Lasers written by Mohammad Nadimi and published by . This book was released on 2018 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The main obstacle in power scaling of the well-known Nd-doped lasers such as Nd:YVO4 is the thermal lensing effect. One of the proposed solutions to effectively alleviate this problem was based on the reduction of heating within the laser crystal. This was extensively investigated with the Nd:YVO4 crystal by pumping the laser at 914 nm instead of the standard pumping at 808 nm wavelength. In context of high power applications, the crystal of Nd:GdVO4 is an interesting alternative to the Nd:YVO4 as it offers the benefits of good spectral features (similar to Nd:YVO4) and much higher thermal conductivity. However, there is only one proof-of-principle work on continuous-wave (CW) Nd:GdVO4 laser using this pumping approach in which an output power of 3.35 W was reported. The full power scaling potential of the Nd:GdVO4 laser crystal to produce high output power has not been demonstrated to date. In this PhD thesis, I addressed this issue and investigated the high power operation of Nd:GdVO4 lasers under a new pumping wavelength of 912 nm. First, the thermal lensing behaviour of a 1063 nm Nd:GdVO4 was studied, both experimentally and by finite element analysis (FEA) method. The thermal lensing strength in Nd:GdVO4 laser under 912 nm pumping was significantly reduced when compared to the Nd:GdVO4 laser with 808 nm pumping or even Nd:YVO4 laser with 914 nm pumping. The next step of this research was focused on high power operation of Nd:GdVO4 lasers where we achieved 19.8 W of output power at 1063 nm. As a side work in the CW regime of operation, the possibility of discrete wavelength tuning and dual-wavelength operation of the Nd:GdVO4 laser were examined by using an intracavity birefringent filter. Discrete wavelength operation at four different wavelengths was demonstrated. Furthermore, for the first time we were able to demonstrate a dual-wavelength operation of the Nd:GdVO4 laser as a 1063 and 1071 nm wavelength pair. The last aspect of this PhD thesis was concentrated on generation of picosecond pulses. We were able to report on the first semiconductor saturable absorber mirror (SESAM) mode-locked (ML) Nd:GdVO4 laser with 912 nm pumping. The laser generated 10.14 W of average output power with the pulse width of 16 ps at the repetition rate of 85.2 MHz. To the best of our knowledge this is the highest average output power ever obtained from any of the SESAM mode-locked Nd-doped solid-state lasers that were pumped around 912 nm.
Download or read book Optics Letters written by and published by . This book was released on 2002 with total page 632 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Applied Science Technology Index written by and published by . This book was released on 1997 with total page 2948 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Applied Nanophotonics written by Sergey V. Gaponenko and published by Cambridge University Press. This book was released on 2019 with total page 453 pages. Available in PDF, EPUB and Kindle. Book excerpt: An accessible yet rigorous introduction to nanophotonics, covering basic principles, technology, and applications in lighting, lasers, and photovoltaics. Providing a wealth of information on materials and devices, and over 150 color figures, it is the 'go-to' guide for students in electrical engineering taking courses in nanophotonics.
Download or read book Ultrafast Lasers written by Martin E. Fermann and published by CRC Press. This book was released on 2002-10-25 with total page 728 pages. Available in PDF, EPUB and Kindle. Book excerpt: Covering high-energy ultrafast amplifiers and solid-state, fiber, and diode lasers, this reference examines recent developments in high-speed laser technology. It presents a comprehensive survey of ultrafast laser technology, its applications, and future trends in various scientific and industrial areas. Topics include: micromachining applications for metals, dielectrics, and biological tissue; advanced electronics and semiconductor processing; optical coherence tomography; multiphoton microscopy; optical sampling and scanning; THz generation and imaging; optical communication systems; absolute phase control of optical signals; and more.
Download or read book Photonics written by Ralf Menzel and published by Springer Science & Business Media. This book was released on 2013-04-18 with total page 895 pages. Available in PDF, EPUB and Kindle. Book excerpt: Deals with the fundamental properties of photon and light beams, both experimentally and theoretically. It covers the essentials of linear interactions and most of the nonlinear interactions between light and matter in both the transparent and absorbing cases. About 4000 references open access to original literature.
Download or read book Strong Field Laser Physics written by Thomas Brabec and published by Springer. This book was released on 2008-08-17 with total page 590 pages. Available in PDF, EPUB and Kindle. Book excerpt: Due to the rapid progress in laser technology a wealth of novel fundamental and applied applications of lasers in atomic and plasma physics have become possible. This book focuses on the interaction of high intensity lasers with matter. It reviews the state of the art of high power laser sources, intensity laser-atom and laser-plasma interactions, laser matter interaction at relativistic intensities, and QED with intense lasers.
Download or read book Photonic Crystals Physics and Technology written by Concita Sibilia and published by Springer Science & Business Media. This book was released on 2009-02-03 with total page 289 pages. Available in PDF, EPUB and Kindle. Book excerpt: The aim of the work is give an overview of the activity in the field of Photonic Crystal developed in the frame of COST P11 action . The main objective of the COST P11 action was to unify and coordinate national efforts aimed at studying linear and nonlinear optical interactions with Photonic Crystals (PCs), without neglecting an important aspect related to the material research as idea and methods of realizations of 3D PC, together with the development and implementation of measurement techniques for the experimental evaluation of their potential applications in different area, as for example telecommunication with novel optical fibers, lasers, nonlinear multi-functionality, display devices, opto-electronics, sensors. The book contains contributions from authors who gave their lecture at the Cost P11 Training School.
Download or read book Ultrashort Laser Pulses in Biology and Medicine written by Markus Braun and published by Springer Science & Business Media. This book was released on 2008-03-15 with total page 326 pages. Available in PDF, EPUB and Kindle. Book excerpt: Learn about the many biological and medical applications of ultrashort laser pulses. The authors highlight and explain how the briefness of these laser pulses permits the tracing of even the fastest processes in photo-active bio-systems. They also present a variety of applications that rely on the high peak intensity of ultrashort laser pulses. Easy-to-follow examples cover non-linear imaging techniques, optical tomography, and laser surgery.
