Download or read book High power Picosecond Pulse Generation from Q switched Diode Lasers written by Sheng-Hui Yang and published by . This book was released on 1996 with total page 430 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Flexible Generation of Picosecond Laser Pulses in the Infrared and Green Spectral Range by Gain Switching of Semiconductor Lasers written by Sina Riecke and published by Cuvillier Verlag. This book was released on 2011-03-15 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt: Picosecond laser pulses find diverse applications for example in material processing as well as in analysis and sensing. Fluorescence lifetime spectroscopy in particular requires pulses with variable repetition rate and moderate pulse energy. While suitable pulses in the red and blue spectral range can be provided by gain-switched laser diodes, the generation of green laser pulses requires a more elaborate setup based on second harmonic generation. The starting point is a gain-switched infrared distributed-feedback laser diode. The optimization of the laser design and the operating conditions allows to generate spectrally narrow picosecond pulses with a peak power above 1 W. Different gain media are compared for further amplification of these pulses, and options for the miniaturization of the master-oscillator power-amplifier system are explored. The resulting intense infrared pulses are then used for second harmonic generation of green picoseconds pulses. Their peak power of above 5 W exceeds all previous green pulse sources with variable repetition rate. In terms of pulse energy and background suppression, the reported green pulses are thus ideally suited for fluorescence lifetime spectroscopy
Download or read book High Voltage Picosecond Pulse Generation Utilizing Lasers written by R. Heintz and published by . This book was released on 1985 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt: A mod-locked Q-switched Nd:YAG laser is used to generate a train of light pulses of approximately 70 picoseconds duration. The energy in these laser pulses are of the order of 2 milli-joules. The train of pulses are then passed through a switchout so that a single pulse is selected. This single pulse then strikes a chromium doped GaAs semiconductor switch which then conducts. If a high voltage supply is connected to one end of the switch and a load is connected to the other end, then the load will observe an electrical pulse which is half the amplitude of the d.c. voltage and of the order of 100-200 picosecond duration. The width of the electrical pulse is determined by the width of the laser pulse and of the characteristics of the transmission line over which the GaAs is mounted. (Author).
Download or read book The Generation and Propagation of Sub picosecond High peak power Laser Pilses written by Alan Michael Braun and published by . This book was released on 1997 with total page 350 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Generating Picosecond Pulses from Q switched Microchip Lasers written by Alexander Craig Butler and published by . This book was released on 2012 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since their first demonstration in the 1960s, picosecond laser pulses have initiated and defined the area of ultrafast laser physics. Their ability to generate a burst of high-intensity, coherent light has opened up areas of science and enabled the observation of events that would otherwise remain out of the realm of human understanding. -- The particular mechanism commonly associated with picosecond pulse generation is mode-locking. These systems are typically complex, bulky and correspondingly expensive. A compact, cheap and robust option that produces comparable pulses would be of great value to the scientific and engineering communities. To this end, we examine the growing area of Q-switched microchip lasers: simple and compact devices that generate sub-nanosecond pulses by virtue of extremely reduced resonator cavity lengths. Incorporation of a passive Q-switch device, a semiconductor saturable absorber mirror or SESAM, enables truly minimal cavity lengths, and therefore minimal pulse durations, to be accessed. -- In this thesis we explore the limits of generating the shortest pulses from such microchip lasers. We develop a comprehensive numerical simulation model, based on the laser rate equations, to effectively model SESAM Q-switched microchip lasers. We incorporate additional phenomena such as two-photon absorption (TPA) in the Q-switch and SESAM etalons to derive a complete picture of the abilities of these micro-lasers. We show that TPA will increasingly affect the performance of these lasers, as shorter pulses are generated, and suspect that our model underestimates its effect on our experimental results. We examine the switching dynamics of the SESAM and describe the role of relaxation oscillations in the switching process, as well as demonstrating controlled partial switching. Scaling dependencies between laser component parameters and laser performance are drawn, providing guidelines for development of these lasers. We examine these relationships in experiment and verify the key relationship between short cavities and short pulses. We demonstrate a laser with record short pulses of 22 ps duration by extending the scaling of these lasers to the shortest demonstrated cavity length of 110 μm. -- To alleviate the low efficiency associated with lasers using thin gain media, we propose, model and develop an energy-scavenging amplification scheme. We demonstrate that a complete, amplified Q-switched microchip laser system has the potential to rival amplified mode-locked systems in generating few-picosecond, microjoule pulses, although practical validation of this will approach require careful laser engineering.
Download or read book Handbook of Laser Technology and Applications Laser design and laser systems written by Colin E. Webb and published by CRC Press. This book was released on 2004 with total page 1282 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 2003-09-04 with total page 600 pages. Available in PDF, EPUB and Kindle. Book excerpt: This collection of authoritative reviews by leading experts provides a broad and instructive introduction to the most advanced techniques for generating coherent light in the mid-infrared region of the spectrum. With a wealth of up-to-date references – also available online.
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 808 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
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 Ultrafast Photonics written by A. Miller and published by CRC Press. This book was released on 2019-08-22 with total page 382 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ultrafast photonics has become an interdisciplinary topic of high international research interest because of the spectacular development of compact and efficient lasers producing optical pulses with durations in the femtosecond time domain. Present day long-haul telecommunications systems are almost entirely based on the transmission of short burst
Download or read book Handbook of Laser Technology and Applications Principles written by Colin E. Webb and published by CRC Press. This book was released on 2004 with total page 1294 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Generation of High power Picosecond Laser Pulses written by and published by . This book was released on 1910 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We present a method of highly dynamic carrier injection into the active zone of a Fabry-Perot laser structure, which enables us to modulate the optical refractive index of the optical waveguide. We will demonstrate experimentally, that the optical refractive index can be changed in such a way, that the laser diode emits light pulses with FWHM around five to ten times smaller and optical peak power up to two orders of magnitude larger than by using normal carrier injection. These extremely improved losing characteristics using cheap and easy to manufacture devices are of great interest for sensor applications.
Download or read book Handbook of Laser Technology and Applications Three Volume Set written by Colin Webb and published by CRC Press. This book was released on 2003-12-01 with total page 2779 pages. Available in PDF, EPUB and Kindle. Book excerpt: The invention of the laser was one of the towering achievements of the twentieth century. At the opening of the twenty-first century we are witnessing the burgeoning of the myriad technical innovations to which that invention has led. The Handbook of Laser Technology and Applications is a practical and long-lasting reference source for scientists a
Download or read book Handbook of Laser Technology and Applications written by Colin Webb and published by CRC Press. This book was released on 2020-09-29 with total page 1266 pages. Available in PDF, EPUB and Kindle. Book excerpt: The invention of the laser was one of the towering achievements of the twentieth century. At the opening of the twenty-first century we are witnessing the burgeoning of the myriad technical innovations to which that invention has led. The Handbook of Laser Technology and Applications is a practical and long-lasting reference source for scientists and engineers who work with lasers. The Handbook provides, a comprehensive guide to the current status of lasers and laser systems; it is accessible to science or engineering graduates needing no more than standard undergraduate knowledge of optics. Whilst being a self-contained reference work, the Handbook provides extensive references to contemporary work, and is a basis for studying the professional journal literature on the subject. It covers applications through detailed case studies, and is therefore well suited to readers who wish to use it to solve specific problems of their own. The first of the three volumes comprises an introduction to the basic scientific principles of lasers, laser beams and non-linear optics. The second volume describes the mechanisms and operating characteristics of specific types of laser including crystalline solid - state lasers, semiconductor diode lasers, fibre lasers, gas lasers, chemical lasers, dye lasers and many others as well as detailing the optical and electronic components which tailor the laser's performance and beam delivery systems. The third volume is devoted to case studies of applications in a wide range of subjects including materials processing, optical measurement techniques, medicine, telecommunications, data storage, spectroscopy, earth sciences and astronomy, and plasma fusion research. This vast compendium of knowledge on laser science and technology is the work of over 130 international experts, many of whom are recognised as the world leaders in their respective fields. Whether the reader is engaged in the science, technology, industrial or medical applications of lasers or is researching the subject as a manager or investor in technical enterprises they cannot fail to be informed and enlightened by the wide range of information the Handbook supplies.
Download or read book Tunable Picosecond Pulse Generation by an N2 Laser Pumped Self Q switched Distributed Feedback Dye Laser written by and published by . This book was released on 1980 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Ultrafast Diode Lasers written by Peter Vasilʹev and published by Artech House Publishers. This book was released on 1995 with total page 296 pages. Available in PDF, EPUB and Kindle. Book excerpt: This timely book combines theory, applications, and projections on ultrafast diode lasers (UDL). A comprehensive treatment of UDLs from basic physical principles to applications in optical fiber communications and ultrafast electronics.
Download or read book Few Cycle Laser Pulse Generation and Its Applications written by Franz X. Kärtner and published by Springer Science & Business Media. This book was released on 2004-09-14 with total page 472 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book covers the physics, technology and applications of short pulse laser sources that generate pulses with durations of only a few optical cycles. The basic design considerations for the different systems such as lasers, parametric amplifiers and external compression techniques which have emerged over the last decade are discussed to give researchers and graduate students a thorough introduction to this field. The existence of these sources has opened many new fields of research that were not possible before. These are UV and EUV generation from table-top systems using high-harmonic generation, frequency metrology enabling optical frequency counting, high-resolution optical coherence tomography, strong-field ultrafast solid-state processes and ultrafast spectroscopy, to mention only a few. Many new applications will follow. The book attempts to give a comprehensive, while not excessive, introduction to this exciting new field that serves both experienced researchers and graduate students entering the field. The first half of the book covers the current physical principles, processes and design guidelines to generate pulses in the optical range comprising only a few cycles of light. Such as the generation of relatively low energy pulses at high repetition rates directly from the laser, parametric generation of medium energy pulses and high-energy pulses at low repetition rates using external compression in hollow fibers. The applications cover the revolution in frequency metrology and high-resolution laser spectroscopy to electric field synthesis in the optical range as well as the emerging field of high-harmonic generation and attosecond science, high-resolution optical imaging and novel ultrafast dynamics in semiconductors. These fields benefit from the strong electric fields accompanying these pulses in solids and gases during events comprising only a few cycles of light.
