Download or read book High frequency Modulation of a Quantum cascade Laser Using a Monolithically Integrated Intracavity Modulator written by and published by . This book was released on with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We report a quantum-cascade laser monolithically integrated with an intracavity modulator which could be operated up to 1 GHz. In contrast to earlier approaches, where the radio frequency (RF) modulation signal was supplied to the entire cavity length of the laser structure, we drive only a relatively small 375-/spl mu/m-long section of the cavity. At the same time, a quasi-continuous-wave signal was supplied to the remaining 1125-/spl mu/m-long section. This modulation scheme resulted in smaller parasitic capacitance effects than what we reported previously, and enabled us to work with lower RF voltages and currents.
Download or read book Quantum Cascade Lasers written by Jérôme Faist and published by Oxford University Press. This book was released on 2013-03-14 with total page 321 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book describes the physics, fabrication technology, and applications of the quantum cascade laser.
Download or read book Design Engineering and Processing of QC Lasers for High Frequency Modulation written by Ariane Calvar and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Quantum Cascade Lasers Based on Intra cavity Frequency Mixing written by Min Jang and published by . This book was released on 2012 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt: Quantum cascade lasers (QCLs) operate due to population inversion on intersubband in unipolar mutiple-quantum-well (MQW) heterostructure. QCLs are considered one of the most flexible and powerful light semiconductor sources in the mid- and far-infrared (IR) wavelength range, covering most of the critical spectral regions relevant to IR applications. InGaAs/InAlAs/InP QCLs are the only semiconductor lasers capable of continuous wave (CW) operation at room temperature (RT) in the spectral range 3.4-12 micron. This dissertation details the development of RT QCLs based on passive nonlinear coupled-quantum-well structures monolithically integrated into mid-IR QCLs to provide a giant nonlinear response for the pumping frequency. The primary focus of short-wavelength approach in this dissertation is to develop of RT InGaAs/InAlAs/InP QCLs for lamda=2.5-3.7 micron region, based on quasi-phase-matched intracavity second harmonic generation (SHG) associated with intersubband transition. Intersubband optical transition can be engineered by the choice of quantum well and barrier thicknesses to provide the appropriate energy levels, optical dipole matrix elements, and electron scattering rates amongst other parameters. Thus, aside from their linear optical properties, resonant intersubband transitions in coupled QW's can also be designed to produce nonlinear optical medium with giant nonlinear optical susceptibilities. In long-wavelength region, at high temperature, the population inversion is reduced between the upper and lower laser levels due to the longitudinal optical (LO) phonon scattering of thermal carriers in the upper laser state and the thermal backfilling of carriers into the lower laser level from the injector state. This dissertation aims to improve an alternative approach for THz QCL sources based on intra-cavity difference frequency generation (DFG) in dual-wavelength mid-IR QCLs with a passive nonlinear structure, designed for giant optical nonlinearity. Further studies describe that Cerenkov DFG scheme allows for extraction of THz radiation along the whole length of the laser waveguide and provides directional THz emission in 1.2-4.5 THz range. An important requirement for many applications, like chemical sensing and molecular spectroscopy, is single-mode emission. We demonstrate single-mode RT DFG THz QCLs operation in 1-5 THz region by employing devices as integrated dual-period DFB lasers, where efficient solid state RT sources do not exist.
Download or read book International Aerospace Abstracts written by and published by . This book was released on 1999 with total page 974 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Radio Frequency Modulation of Low Dissipation Distributed Feedback Quantum Cascade Lasers written by Borislav Hinkov 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 Room Temperature Operation of Quantum Cascade Lasers Monolithically Integrated Onto a Lattice mismatched Substrate written by Rowel Canaon Go and published by . This book was released on 2018 with total page 35 pages. Available in PDF, EPUB and Kindle. Book excerpt: A small sample of 2 cm2 size was taken from a 6-inch wafer and processed into ridge-waveguide chips 3 mm x 30 [micrometer] in size. Lateral current injection scheme was utilized due to an insulating M-buffer layer. Preliminary reliability testing up to 200 minutes of runtime showed no sign of power degradation. Laser chips with high reflection (HR) coating showed optical power over 200 mW of total peak power at cryogenic temperature (78 K), with lasing seen up to 230 K. In this temperature range, the measured characteristic temperatures of T0 ≈ 460 K and T1 ≈ 210 K describes the temperature dependence for threshold current and slope efficiency. Adding a partial HR coating (56%) on the front facet extended the lasing range above room temperature (303 K). This thesis will also discuss the preliminary cryogenic temperature result of the first InP-based QCL grown on latticemismatched silicon (Si) substrate.
Download or read book Chemical Abstracts written by and published by . This book was released on 2002 with total page 2692 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Development of Terahertz Frequency Quantum Cascade Laser written by Mohammed Salih and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: THz QCLs, based on a three-well resonant-phonon depopulation active region design, have been studied in depth using semi-insulating surface plasmon waveguides. Lasing frequencies between 2.3 to 4.0 THz have been investigated, together with a detailed evaluation of the effect of cavity length on devices performance. The effect of reducing the thickness of the THz QCL active region from 10 to 5 IJm was investigated, and the influence of active region thickness on lattice temperatures compared. Thinner active regions potentially make it possible to obtain continuous-wave (CW) operation from three-well, resonant-phonon depopulation QCLs, which is a requirement for many applications. It was demonstrated that the laser cavity of edge-emitting THz QCLs could be defined using an etched rather than a cleaved facet. Three emission frequencies ( - 3.0, - 3.5 and - 4.0 THz) with two different facet angles (et:> = - 50° and et:> = - 42°) were studied and device performance were compared. The new THz QCL devices with sloped facets could open up the possibility of monolithic integration of QCLs into terahertz circuits. They also remove the requirement for THz QCLs to be fabricated perpendicular to cleavage planes of the underlying crystal structure. From the demonstration of lasing from THz QCLs with angled facets, the possibility of coupling surface acoustic waves (SAWs) with THz QCLs is investigated. The aim was to use SAWs propagating through upper surface of the waveguide of the THz QCL to introduce modulation of the gain region. This would have significant application to spectroscopy at THz frequencies. SAW propagate across a QCL mesa was demonstrated, and fully investigated devices were fabricated and tested.
Download or read book Terahertz Quantum Cascade Lasers written by Owen Peter Marshall 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 Science Abstracts written by and published by . This book was released on 1993 with total page 980 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Diode Lasers and Photonic Integrated Circuits written by Larry A. Coldren and published by John Wiley & Sons. This book was released on 2012-03-02 with total page 752 pages. Available in PDF, EPUB and Kindle. Book excerpt: Diode Lasers and Photonic Integrated Circuits, Second Edition provides a comprehensive treatment of optical communication technology, its principles and theory, treating students as well as experienced engineers to an in-depth exploration of this field. Diode lasers are still of significant importance in the areas of optical communication, storage, and sensing. Using the the same well received theoretical foundations of the first edition, the Second Edition now introduces timely updates in the technology and in focus of the book. After 15 years of development in the field, this book will offer brand new and updated material on GaN-based and quantum-dot lasers, photonic IC technology, detectors, modulators and SOAs, DVDs and storage, eye diagrams and BER concepts, and DFB lasers. Appendices will also be expanded to include quantum-dot issues and more on the relation between spontaneous emission and gain.
Download or read book Optics Letters written by and published by . This book was released on 2007 with total page 640 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Physics briefs written by and published by . This book was released on 1989 with total page 840 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Frontiers in Optics and Photonics written by Federico Capasso and published by Walter de Gruyter GmbH & Co KG. This book was released on 2021-06-08 with total page 783 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a cutting-edge research overview on the latest developments in the field of Optics and Photonics. All chapters are authored by the pioneers in their field and will cover the developments in Quantum Photonics, Optical properties of 2D Materials, Optical Sensors, Organic Opto-electronics, Nanophotonics, Metamaterials, Plasmonics, Quantum Cascade lasers, LEDs, Biophotonics and biomedical photonics and spectroscopy.
Download or read book Semiconductor Laser Engineering Reliability and Diagnostics written by Peter W. Epperlein and published by John Wiley & Sons. This book was released on 2013-01-25 with total page 522 pages. Available in PDF, EPUB and Kindle. Book excerpt: This reference book provides a fully integrated novel approach to the development of high-power, single-transverse mode, edge-emitting diode lasers by addressing the complementary topics of device engineering, reliability engineering and device diagnostics in the same book, and thus closes the gap in the current book literature. Diode laser fundamentals are discussed, followed by an elaborate discussion of problem-oriented design guidelines and techniques, and by a systematic treatment of the origins of laser degradation and a thorough exploration of the engineering means to enhance the optical strength of the laser. Stability criteria of critical laser characteristics and key laser robustness factors are discussed along with clear design considerations in the context of reliability engineering approaches and models, and typical programs for reliability tests and laser product qualifications. Novel, advanced diagnostic methods are reviewed to discuss, for the first time in detail in book literature, performance- and reliability-impacting factors such as temperature, stress and material instabilities. Further key features include: practical design guidelines that consider also reliability related effects, key laser robustness factors, basic laser fabrication and packaging issues; detailed discussion of diagnostic investigations of diode lasers, the fundamentals of the applied approaches and techniques, many of them pioneered by the author to be fit-for-purpose and novel in the application; systematic insight into laser degradation modes such as catastrophic optical damage, and a wide range of technologies to increase the optical strength of diode lasers; coverage of basic concepts and techniques of laser reliability engineering with details on a standard commercial high power laser reliability test program. Semiconductor Laser Engineering, Reliability and Diagnostics reflects the extensive expertise of the author in the diode laser field both as a top scientific researcher as well as a key developer of high-power highly reliable devices. With invaluable practical advice, this new reference book is suited to practising researchers in diode laser technologies, and to postgraduate engineering students.
Download or read book Ceramic Lasers written by Akio Ikesue and published by Cambridge University Press. This book was released on 2013-05-23 with total page 459 pages. Available in PDF, EPUB and Kindle. Book excerpt: Until recently, ceramic materials were considered unsuitable for optics due to the numerous scattering sources, such as grain boundaries and residual pores. However, in the 1990s the technology to generate a coherent beam from ceramic materials was developed, and a highly efficient laser oscillation was realized. In the future, the technology derived from the development of the ceramic laser could be used to develop new functional passive and active optics. Co-authored by one of the pioneers of this field, the book describes the fabrication technology and theoretical characterization of ceramic material properties. It describes novel types of solid lasers and other optics using ceramic materials to demonstrate the application of ceramic gain media in the generation of coherent beams and light amplification. This is an invaluable guide for physicists, materials scientists and engineers working on laser ceramics.
