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Book Optimization of broad area GaAs diode lasers for high powers and high efficiencies in the temperature range 200 220 K

Download or read book Optimization of broad area GaAs diode lasers for high powers and high efficiencies in the temperature range 200 220 K written by Carlo Frevert and published by Cuvillier Verlag. This book was released on 2019-07-11 with total page 174 pages. Available in PDF, EPUB and Kindle. Book excerpt: This work focuses on the development of AlGaAs-based diode laser (DL) bars optimized for reaching highest powers and efficiencies at low operation temperatures. Specifically, the quasi continuous wave (QCW) pumping of cryogenically cooled Yb:YAG solid-state lasers is targeted, setting requirements on the wavelength (940 nm), the pulse conditions (pulse length 1.2 ms) and frequency (10 Hz) as well as the lowest DL operating temperature THS ~ 200 K, consistent with economic cooling. High fill-factor bars for QCW operation are to reach high optical performance with optical output powers of P  1.5 kW and power conversion efficiencies of ŋE  60% at these power levels. Understanding the efficiency-limiting factors and the behavior at lower temperatures is necessary to design these devices. Optimizations are performed iteratively in three stages. First, vertical epitaxial designs are studied theoretically, adjusted to the targeted operation temperatures and specific laser parameters are extracted. Secondly, resulting vertical designs are processed into low power single emitters and their electro-optical behavior at low currents is experimentally assessed over a wide range of temperatures. The obtained laser parameters characteristic to the vertical design are then used to extrapolate the laser's performance up to the high targeted currents. Finally, vertical designs promising to reach the targeted values for power and efficiency are processed into high power single emitters and bars which are measured up to the highest currents. Eventually, laser bars are fabricated reaching output powers of 2 kW and efficiencies of 61% at 1.5 kW at an operation temperature of 203 K.

Book Epitaxial Design Optimizations for Increased Efficiency in GaAs Based High Power Diode Lasers

Download or read book Epitaxial Design Optimizations for Increased Efficiency in GaAs Based High Power Diode Lasers written by Thorben Kaul and published by Cuvillier Verlag. This book was released on 2021-04-09 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt: This work presents progress in the root-cause analysis of power saturation mechanisms in continuous wave (CW) driven GaAs-based high-power broad area diode lasers operated at 935 nm. Target is to increase efficiency at high optical CW powers by epitaxial design. The novel extreme triple asymmetric (ETAS) design was developed and patented within this work to equip diode lasers that use an extremely thin p-waveguide with a high modal gain. An iterative variation of diode lasers employing ETAS designs was used to experimentally clarify the impact of modal gain on the temperature dependence of internal differential quantum efficiency (IDQE) and optical loss. High modal gain leads to increased free carrier absorption from the active region. However, less power saturation is observed, which must then be attributed to an improved temperature sensitivity of the IDQE. The effect of longitudinal spatial hole burning (LSHB) leads to above average non-linear carrier loss at the back facet of the device. At high CW currents the junction temperature rises. Therefore, not only the asymmetry of the carrier profile increases but also the average carrier density in order to compensate for the decreased material gain and increased threshold gain. This carrier non-pinning effect above threshold is found in this work to enhance the impact of LSHB already at low currents, leading to rapid degradation of IDQE with temperature. This finding puts LSHB into a new context for CW-driven devices as it emphasizes the importance of low carrier densities at threshold. The carrier density was effectively reduced by applying the novel ETAS design. This enabled diode lasers to be realized that show minimized degradation of IDQE with temperature and therefore improved performance in CW operation.

Book Photonics

    Book Details:
  • Author : Ralf Menzel
  • Publisher : Springer Science & Business Media
  • Release : 2013-04-18
  • ISBN : 3662045214
  • Pages : 895 pages

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.

Book Conference on Lasers and Electro optics Europe

Download or read book Conference on Lasers and Electro optics Europe written by and published by . This book was released on 2005 with total page 798 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Solid State Lasers and Applications

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 674 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.

Book Handbook of Lasers

Download or read book Handbook of Lasers written by Marvin J. Weber and published by CRC Press. This book was released on 2019-04-30 with total page 1240 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lasers continue to be an amazingly robust field of activity. Anyone seeking a photon source is now confronted with an enormous number of possible lasers and laser wavelengths to choose from, but no single, comprehensive source to help them make that choice. The Handbook of Lasers provides an authoritative compilation of lasers, their properties, and original references in a readily accessible form. Organized by lasing media-solids, liquids, and gases-each section is subdivided into distinct laser types. Each type carries a brief description, followed by tables listing the lasing element or medium, host, lasing transition and wavelength, operating properties, primary literature citations, and, for broadband lasers, reported tuning ranges. The importance and value of the Handbook of Lasers cannot be overstated. Serving as both an archive and as an indicator of emerging trends, it reflects the state of knowledge and development in the field, provides a rapid means of obtaining reference data, and offers a pathway to the literature. It contains data useful for comparison with predictions and for developing models of processes, and may reveal fundamental inconsistencies or conflicts in the data.

Book Lidar Remote Sensing for Environmental Monitoring

Download or read book Lidar Remote Sensing for Environmental Monitoring written by and published by . This book was released on 2006 with total page 422 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Laser Physics

    Book Details:
  • Author :
  • Publisher :
  • Release : 2009
  • ISBN :
  • Pages : 398 pages

Download or read book Laser Physics written by and published by . This book was released on 2009 with total page 398 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Chinese Physics Letters

Download or read book Chinese Physics Letters written by and published by . This book was released on 2007 with total page 578 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Advanced Solid State Photonics

Download or read book Advanced Solid State Photonics written by and published by . This book was released on 2003 with total page 478 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book ICO20

    Book Details:
  • Author : International Commission for Optics
  • Publisher : SPIE-International Society for Optical Engineering
  • Release : 2005
  • ISBN :
  • Pages : 660 pages

Download or read book ICO20 written by International Commission for Optics and published by SPIE-International Society for Optical Engineering. This book was released on 2005 with total page 660 pages. Available in PDF, EPUB and Kindle. Book excerpt: Proceedings of SPIE present the original research papers presented at SPIE conferences and other high-quality conferences in the broad-ranging fields of optics and photonics. These books provide prompt access to the latest innovations in research and technology in their respective fields. Proceedings of SPIE are among the most cited references in patent literature.

Book Handbook of Laser Wavelengths

Download or read book Handbook of Laser Wavelengths written by Marvin J. Weber and published by CRC Press. This book was released on 2018-10-08 with total page 796 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume represents the most complete, up-to-date compilation of wavelengths of lasers in all media. Divided by type - solid, liquid, and gas - and listed in order of increasing wavelength, Handbook of Laser Wavelengths includes: crystalline paramagnetic ion lasers glass lasers color center lasers semiconductor lasers polymer lasers liquid and solid-state dye lasers rare earth liquid lasers neutral atom, ion, and molecular gas lasers extreme ultraviolet and soft X-ray lasers free electron lasers nuclear-pumped lasers lasers in nature lasers without inversion Brief descriptions of each type of laser are presented, followed by tables listing the laser wavelength, lasing element or medium, host, transition, and primary literature citations. A special section on commercial lasers is an added featured. Handbook of Laser Wavelengths singularly serves as the essential reference for scientists and engineers searching for laser sources for specific applications as well as a survey of the developments that have occurred since the advent of the laser.

Book High Power Continuous Wave Quantum Cascade Lasers with Increased Ridge Width

Download or read book High Power Continuous Wave Quantum Cascade Lasers with Increased Ridge Width written by Ankesh Mahesh Kumar Todi and published by . This book was released on 2017 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt: Quantum Cascade Lasers have recently gained considerable attention for their capability to emit infrared radiation in a broad infrared spectral region, very compact dimensions, and high optical power/efficiency. Increasing continuous wave optical power is one of the main research directions in the field. A straightforward approach to increasing optical power in the pulsed regime is to increase number of stages in the cascade structure. However, due to a low active region thermal conductivity, the increase in number of stages leads to active region overheating in continuous wave operation. In this work, an alternative approach to power scaling with device dimensions is explored: number of stages is reduced to reduce active region thermal resistance, while active region lateral size is increased for reaching high optical power level. Using this approach, power scaling for active region width increase from 10[micrometer] to 20[micrometer] is demonstrated for the first time. An analysis based on a simple semi-empirical model suggests that laser power can be significantly improved by increasing characteristic temperature T0 that describes temperature dependence of laser threshold current density.