Download or read book Passively Mode locked Semiconductor Lasers for All optical Applications written by Josué Amílcar Parra Cetina and published by . This book was released on 2014 with total page 143 pages. Available in PDF, EPUB and Kindle. Book excerpt: The recent increase of internet traffic is creating demand for higher bandwidth in telecommunication networks. In order to satisfy this ever increasing demand for bandwidth, it is necessary to investigate new devices and technologies for all-optical signal processing that allow increasing the transmission data rate and the capacity for the current and future optical networks. Optical time division multiplexing (OTDM) is a widely deployed technique that allows increasing the bit rate and capacity of optical networks. In OTDM networks the regeneration and the demultiplexing of the data channels are two common and important functions normally carried out. However, they require a clock signal, which is usually implemented by optoelectronics components, making a system expensive, bulky and difficult to implement. In order to provide a solution to this issue, the focus of this thesis is to investigate all-optical clock recovery by using external injection locking of passively semiconductor mode-locked lasers. In particular, quantum-dash mode-locked laser diodes (QDash-MLLDs) are studied. These lasers can generate optical pulses with durations in the order of picoseconds and femtoseconds using only DC-bias with no need for external modulation. Besides, they are attractive due to their simplicity of operation, low power consumption, fast carrier dynamics and compactness. Furthermore, they provide a narrow radio frequency beating linewidth, resulting in a small amount of phase noise and low timing jitter. In this thesis, all-optical clock recovery of data signals at base bit rate (40 Gb/s) and high bit rates (up to 320 Gb/s) was achieved using QDash-MLLDs. The recovered clocks from the different data input signals considered in this thesis feature low values of timing jitter, which are compliant with the minimum requirements for practical applications. Furthermore, the recovered clocks at high speed are used to demultiplex signals to tributaries of 40 Gb/s, achieving error free performance. Finally, investigation of the QDash-MLLD dynamics demonstrated that the laser provides a very fast locking time (25 ns) when synchronised to data signals which enables it as a solution to optical burst/packet switched networks. All these results contribute to demonstrate that the laser is an extremely reliable, cost-effective and a green solution for all-optical signal processing.
Download or read book Passively Mode Locked Semiconductor Lasers written by Lina Jaurigue and published by Springer. This book was released on 2017-06-22 with total page 206 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis investigates the dynamics of passively mode-locked semiconductor lasers, with a focus on the influence of optical feedback on the noise characteristics. The results presented here are important for improving the performance of passively mode-locked semiconductor lasers and, at the same time, are relevant for understanding delay-systems in general. The semi-analytic results developed are applicable to a broad range of oscillatory systems with time-delayed feedback, making the thesis of relevance to various scientific communities. Passively mode-locked lasers can produce pulse trains and have applications in the contexts of optical clocking, microscopy and optical data communication, among others. Using a system of delay differential equations to model these devices, a combination of numerical and semi-analytic methods is developed and used to characterize this system.
Download or read book Quantum Dot Based Mode locked Semiconductor Lasers and Applications written by Jimyung Kim and published by . This book was released on 2010 with total page 115 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this dissertation, self-assembled InAs/InGaAs quantum dot Fabry-Pérot lasers and mode-locked lasers are investigated. The mode-locked lasers investigated include monolithic and curved two-section devices, and colliding pulse mode-locked diode lasers. Ridge waveguide semiconductor lasers have been designed and fabricated by wet etching processes. Electroluminescence of the quantum dot lasers is studied. Cavity length dependent lasing via ground state and/or excited state transitions is observed from quantum dot lasers and the optical gain from both transitions is measured. Stable optical pulse trains via ground and excited state transitions are generated using a grating coupled external cavity with a curved two-section device. Large differences in the applied reverse bias voltage on the saturable absorber are observed for stable mode-locking from the excited and ground state mode-locking regimes. The optical pulses from quantum dot mode-locked lasers are investigated in terms of chirp sign and linear chirp magnitude. Upchirped pulses with large linear chirp magnitude are observed from both ground and excited states. Externally compressed pulse widths from the ground and excited states are 1.2 ps and 970 fs, respectively. Ground state optical pulses from monolithic mode-locked lasers e.g., two-section devices and colliding pulse mode-locked lasers, are also studied. Transformed limited optical pulses (~4.5 ps) are generated from a colliding pulse mode-locked semiconductor laser. The above threshold linewidth enhancement factor of quantum dot Fabry-Pérot lasers is measured using the continuous wave injection locking method. A strong spectral dependence of the linewidth enhancement factor is observed around the gain peak. The measured linewidth enhancement factor is highest at the gain peak, but becomes lower 10 nm away from the gain peak. The lowest linewidth enhancement factor is observed on the anti-Stokes side. The spectral dependence of the pulse duration from quantum dot based mode-locked lasers is also observed. Shorter pulses and reduced linear chirp are observed on the anti-Stokes side and externally compressed 660 fs pulses are achieved in this spectral regime. A novel clock recovery technique using passively mode-locked quantum dot lasers is investigated. The clock signal (~4 GHz) is recovered by injecting an interband optical pulse train to the saturable absorber section. The excited state clock signal is recovered through the ground state transition and vice-versa. Asymmetry in the locking bandwidth is observed. The measured locking bandwidth is 10 times wider when the excited state clock signal is recovered from the ground state injection, as compared to recovering a ground state clock signal from excited state injection.
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 Towards Monolithic Semiconductor Photonic Crystal Passively Mode Locked Laser for Two photon Microscopy written by Altamash Janjua and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Semiconductor Monolithic Passively Mode Locked Lasers (MMLLs) have been demonstrated and have a variety of applications including sensing, in optical communications and optical clock generation. The major advantage that these semiconductor light sources possess is their compact size, high efficiency, low cost and robustness. Also the ability to access different wavelengths using various semiconductor materials is a big advantage. The inability to get these lasers to operate at low repetition rates and the limited peak output power of the pulses are the two major limitations of these lasers. The repetition rate is inversely proportional to the semiconductor laser cavity length. The lowest repetition rate in current MMLLs is around 1GHz. This rate is limited by the complexity involved in the fabrication of centimeter long semiconductor laser cavities. The material loss, dispersion and carrier radiative recombination lifetime also limit the output repetition rate. Lower repetition rate lasers can be used in low frequency integrated optical circuits and also for imaging especially for Two-Photon Microscopy (TPM). TPM works by exciting florescence dyes using two photons instead of one. This requires pulsed lasers with high peak power and high energy per pulse. TPM is currently done by using expensive and bulky Ti:Sapphire mode locked lasers that can produce subpicosecond pulses at a repetition rate of order of 100 MHz. The possible use of semiconductor lasers for this application can transform this field by dramatically reducing the cost of imaging and allowing for dramatically smaller sized and more mobile imaging solutions. One potential way to reduce the repetition rate of the lasers without increasing the physical cavity length is to incorporate a slow light photonic crystal structure inside the lasers cavity. Such a laser cavity will have a group index that is much larger than the material refractive index thereby giving a longer optical path length for the same physical length of the device. The incorporation of the photonic crystal will also allow the possibility to do dispersion engineering within the laser cavity and to enable pulse compression. Both these effects can increase the two-photon excitation efficiency for TPM. In this work we highlight the design and progress towards the development of a monolithic semiconductor photonic crystal passively mode locked laser for two-photon microscopy.
Download or read book Mode locked Lasers Introduction To Ultrafast Semiconductor And Fiber Lasers written by Niloy K Dutta and published by World Scientific. This book was released on 2024-05-21 with total page 325 pages. Available in PDF, EPUB and Kindle. Book excerpt: This invaluable book provides a comprehensive treatment of the design and application of Mode Locked Lasers and Short Pulse Generation. With the advances in semiconductor laser and fiber laser technologies in the 1980s to now, these devices have been made compact, refined, and developed for a wide range of applications including further scientific studies.Semiconductor mode-locked lasers are stable pulse sources and can be made over a range of wavelengths where laser operation is feasible. Rare earth doped fiber lasers or planar waveguides extend this range further and can provide compact pulsed sources. The principles of operation, analysis, design and fabrication of these sources are described. Recent results on high repetition rate and high-power pulse generation from these compacts sources are also described, together with current and future directions of application of these types of laser sources.Mode-Locked Lasers: Introduction to Ultrafast Semiconductor and Fiber Lasers is self-contained and unified in presentation. It can be used as an advanced text by graduate students and by practicing engineers. It is also suitable for non-experts who wish to have an overview of mode-locked lasers and pulse generation. The explanations in the book are detailed enough to capture the interest of the curious reader and complete enough to provide the necessary background to explore the subject further.
Download or read book Dynamics and Stochastic Properties of Passively Mode locked Semiconductor Lasers Subject to Optical Feedback written by Lina Jaurigue and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Development and Characterisation of an Actively Mode locked Semiconductor Fibre Laser Incorporating a Nonlinear Optical Loop Mirror Operating at 10 GHz to 160 GHz written by Xing Hua Cai 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 Investigation of Single Section InAs InP Quantum Dot Mode Locked Lasers written by Zhejing Jiao and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Mode locking of Lasers written by Peter W. Smith and published by Pergamon. This book was released on 1974 with total page 132 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Solid State Lasers and Applications written by Alphan Sennaroglu and published by CRC Press. This book was released on 2017-12-19 with total page 548 pages. Available in PDF, EPUB and Kindle. Book excerpt: Because of the favorable characteristics of solid-state lasers, they have become the preferred candidates for a wide range of applications in science and technology, including spectroscopy, atmospheric monitoring, micromachining, and precision metrology. Presenting the most recent developments in the field, Solid-State Lasers and Applications focuses on the design and applications of solid-state laser systems. With contributions from leading international experts, the book explores the latest research results and applications of solid-state lasers as well as various laser systems. The beginning chapters discuss current developments and applications of new solid-state gain media in different wavelength regions, including cerium-doped lasers in the ultraviolet range, ytterbium lasers near 1μm, rare-earth ion-doped lasers in the eye-safe region, and tunable Cr2+:ZnSe lasers in the mid-infrared range. The remaining chapters study specific modes of operation of solid-state laser systems, such as pulsed microchip lasers, high-power neodymium lasers, ultrafast solid-state lasers, amplification of femtosecond pulses with optical parametric amplifiers, and noise characteristics of solid-state lasers. Solid-State Lasers and Applications covers the most important aspects of the field to provide current, comprehensive coverage of solid-state lasers.
Download or read book Vertical External Cavity Surface Emitting Lasers written by Michael Jetter and published by John Wiley & Sons. This book was released on 2021-09-16 with total page 584 pages. Available in PDF, EPUB and Kindle. Book excerpt: Vertical External Cavity Surface Emitting Lasers Provides comprehensive coverage of the advancement of vertical-external-cavity surface-emitting lasers Vertical-external-cavity surface-emitting lasers (VECSELs) emit coherent light from the infrared to the visible spectral range with high power output. Recent years have seen new device developments – such as the mode-locked integrated (MIXSEL) and the membrane external-cavity surface emitting laser (MECSEL) – expand the application of VECSELs to include laser cooling, spectroscopy, telecommunications, biophotonics, and laser-based displays and projectors. In Vertical External Cavity Surface Emitting Lasers: VECSEL Technology and Applications, leading international research groups provide a comprehensive, fully up-to-date account of all fundamental and technological aspects of vertical external cavity surface emitting lasers. This unique book reviews the physics and technology of optically-pumped disk lasers and discusses the latest developments of VECSEL devices in different wavelength ranges. Topics include OP-VECSEL physics, continuous wave (CW) lasers, frequency doubling, carrier dynamics in SESAMs, and characterization of nonlinear lensing in VECSEL gain samples. This authoritative volume: Summarizes new concepts of DBR-free and MECSEL lasers for the first time Covers the mode-locking concept and its application Provides an overview of the emerging concept of self-mode locking Describes the development of next-generation OPS laser products Vertical External Cavity Surface Emitting Lasers: VECSEL Technology and Applications is an invaluable resource for laser specialists, semiconductor physicists, optical industry professionals, spectroscopists, telecommunications engineers and industrial physicists.
Download or read book Dynamics of Quantum Dot Lasers written by Christian Otto and published by Springer Science & Business Media. This book was released on 2014-01-21 with total page 301 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis deals with the dynamics of state-of-the-art nanophotonic semiconductor structures, providing essential information on fundamental aspects of nonlinear dynamical systems on the one hand, and technological applications in modern telecommunication on the other. Three different complex laser structures are considered in detail: (i) a quantum-dot-based semiconductor laser under optical injection from a master laser, (ii) a quantum-dot laser with optical feedback from an external resonator, and (iii) a passively mode-locked quantum-well semiconductor laser with saturable absorber under optical feedback from an external resonator. Using a broad spectrum of methods, both numerical and analytical, this work achieves new fundamental insights into the interplay of microscopically based nonlinear laser dynamics and optical perturbations by delayed feedback and injection.
Download or read book High Power Ultra short Pulse Quantum dot Lasers written by Daniil Nikitichev and published by . This book was released on 2012-08-12 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this thesis, novel multi-section laser diodes based on quantum-dot material are designed and investigated which exhibit a number of advantages such as low threshold current density; temperature-insensitivity and suppress carrier diffusion due to discrete nature of density of state of quantum-dots. The spectral versatility in the range of 1.1 μm - 1.3 μm wavelengths is demonstrated through novel mode-locking regimes such as dual-wavelength mode-locking, wavelength bistability and broad tunability. Moreover, broad pulse repetition rate tuning using an external cavity configuration is presented. A high peak power of 17.7 W was generated from the quantum-dot laser as a result of the tapered geometry of the gain section of the laser has led to successful application of such device for two-photon imaging. Dual-wavelength mode-locking is demonstrated via ground (?=1180 nm) and excited (?=1263 nm) spectral bands with optical pulses from both states simultaneously in the 5-layer quantum-dot two-section diode laser. The widest spectral separation of 83 nm between the modes was achieved in a dual-wavelength mode-locked non-vibronic laser. Power and wavelength bistability are achieved in a mode-locked multi-section laser which active region incorporates non-identical QD layers grown by molecular beam epitaxy. As a result the wavelength can be electronically controlled between 1245 nm and 1290 nm by applying different voltages to the saturable absorber. Mode-locked or continuous-wave regimes are observed for both wavelengths over a 260 mA - 330 mA current ranges with average power up to 28 mW and 31 mW, respectively. In mode-locked regime, a repetition rate of 10 GHz of optical pulses as short as 4 ps is observed. Noticeable hysteresis of average power for different bias conditions is also demonstrated. The wavelength and power bistability in QD lasers are potentially suitable for flip-flop memory application. In addition, a unique mode-locked regime at expense of the reverse bias with 50 nm wavelength tuning range from 1245 nm to 1290 nm is also presented. Broad repetition rate tunability is shown from quantum-dot external cavity mode-locked 1.27 μm laser. The repetition rate from record low of 191 MHz to 1 GHz from fundamental mode-locking was achieved. Harmonic mode-locking allows further to increase tuning up to 6.8 GHz (34th-order harmonic) from 200 MHz fundamental mode-locking. High peak power of 1.5 W can be generated directly from two-section 4 mm long laser with bent waveguide at angle of 7° at 1.14 GHz repetition rate without the use of any pulse compression and optical amplifier. Stable mode-locking with an average power up to 60 mW, corresponding to 25 pJ pulse energy is also obtained at a repetition frequency of 2.4 GHz. The minimum time-bandwidth product of 1.01 is obtained with the pulse duration of 8.4 ps. Novel tapered quantum-dot lasers with a gain-guided geometry operating in a passively mode-locked regime have been investigated, using structures that incorporated either 5 or 10 quantum dot layers. The peak power of 3.6 W is achieved with pulse duration of 3.2 ps. Furthermore, the record peak power of 17.7 W and transform limited pulses of 672 fs were achieved with optimized structure. The generation of picosecond pulses with high average power of up to 209 mW was demonstrated, corresponding to 14.2 pJ pulse energy. The improved optical parameters of the tapered laser enable to achieve nonlinear images of fluorescent beads. Thus it is for the first time that QD based compact monolithic device enables to image biological samples using two-photon microscopy imaging technique.
Download or read book Semiconductor Disk Lasers written by Oleg G. Okhotnikov and published by John Wiley & Sons. This book was released on 2010-03-30 with total page 330 pages. Available in PDF, EPUB and Kindle. Book excerpt: This timely publication presents a review of the most recent developments in the field of Semiconductor Disk Lasers. Covering a wide range of key topics, such as operating principles, thermal management, nonlinear frequency conversion, semiconductor materials, short pulse generation, electrical pumping, and laser applications, the book provides readers with a comprehensive account of the fundamentals and latest advances in this rich and diverse field. In so doing, it brings together contributions from world experts at major collaborative research centers in Europe and the USA. Each chapter includes a tutorial style introduction to the selected topic suitable for postgraduate students and scientists with a basic background in optics - making it of interest to a wide range of scientists, researchers, engineers and physicists working and interested in this rapidly developing field. It will also serve as additional reading for students in the field.
Download or read book Strong Optical Injection Locking of Edge emitting Lasers and Its Applications written by Hyuk-Kee Sung and published by . This book was released on 2006 with total page 318 pages. Available in PDF, EPUB and Kindle. Book excerpt: Semiconductor lasers are essential components that enable high-speed long-haul communication and have been widely used for various applications in photonics technology. Semiconductor lasers under optical injection locking exhibit superior performance over free-running lasers and provide useful applications not achievable through the free-running lasers. The performance of injection-locked lasers has been found to be significantly improved with stronger injection. In this dissertation, the characteristics and applications of semiconductor lasers under strong optical injection locking are presented and analyzed in various aspects. First, ultra-strong (injection ratio R ̃10 dB) optical injection locking properties are investigated experimentally and theoretically. Direct modulation responses of ultra-strong optical injection-locked distributed feedback (DFB) lasers show three distinctive modulation characteristics depending on frequency detuning values. These different optical properties and electric modulation characteristics can be utilized in various applications such as analog fiber optic link, broadband digital communications, RF photonics and opto-electronic oscillators (OEOs). Using the strong injection-locked lasers, a novel single sideband generation has been demonstrated. A modulation sideband on the longer wavelength side is enhanced due to the resonant amplification by the slave laser's cavity mode, resulting in a 12-dB asymmetry at 20-GHz RF modulation. The dispersion limited RF bandwidth has been greatly increased by maintaining the variation of fiber transmission response within 7 dB up to 20-GHz RF carrier frequency over 80-km fiber transmission. Second, to improve fiber optic link performances, gain-lever distributed Bragg reflector (DBR) lasers have been fabricated. With a gain-lever modulation, 9-dB increase of a link gain has been achieved compared with a standard modulation.
Download or read book Ultrafast Lasers Based on Quantum Dot Structures written by Edik U. Rafailov and published by John Wiley & Sons. This book was released on 2011-04-08 with total page 243 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this monograph, the authors address the physics and engineering together with the latest achievements of efficient and compact ultrafast lasers based on novel quantum-dot structures and devices. Their approach encompasses a broad range of laser systems, while taking into consideration not only the physical and experimental aspects but also the much needed modeling tools, thus providing a holistic understanding of this hot topic.
