Injection Lasers for High Data Rate Optical Communications PDF Download
Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download Injection Lasers for High Data Rate Optical Communications PDF full book. Access full book title Injection Lasers for High Data Rate Optical Communications by I. Ladany. Download full books in PDF and EPUB format.
Author: I. Ladany Publisher: ISBN: Category : Languages : en Pages : 87
Book Description
An outline is given of the basic parameters which control the operation and life expectancy of cw laser diodes. This includes a different approach to the laser design problem than that generally used and leads to a modified expression for the threshold current density. Results of this analysis are used to develop a cw laser structure that combines a low threshold with a low vertical beam spread, the latter being essential to the achievement of low coupling losses needed in fiber-optic communication systems. Other design requirements are reviewed, and electrical and optical performance data of lasers developed under this contract are presented. Based on extensive experimental measurements, the reliability aspects of cw lasers are discussed. Facet erosion is shown to be a major failure mode, and methods are given for limiting the influence of this effect. With a suitable coating applied to the facet, lasers fabricated during this contract have accumulated 6000 hours of life without significant output decrease. Similar lasers, without facet protection, have accumulated more than 10,000 hours of operating time with output decreasing gradually, as a consequence of facet erosion. A laser system has been developed, which includes thermal stabilization utilizing thermoelectric coolers and fan coooling for heat removal from the hot end of the thermoelectric module. Convection cooling for that purpose has been demonstrated to be adequate under less extreme ambients.
Author: I. Ladany Publisher: ISBN: Category : Languages : en Pages : 87
Book Description
An outline is given of the basic parameters which control the operation and life expectancy of cw laser diodes. This includes a different approach to the laser design problem than that generally used and leads to a modified expression for the threshold current density. Results of this analysis are used to develop a cw laser structure that combines a low threshold with a low vertical beam spread, the latter being essential to the achievement of low coupling losses needed in fiber-optic communication systems. Other design requirements are reviewed, and electrical and optical performance data of lasers developed under this contract are presented. Based on extensive experimental measurements, the reliability aspects of cw lasers are discussed. Facet erosion is shown to be a major failure mode, and methods are given for limiting the influence of this effect. With a suitable coating applied to the facet, lasers fabricated during this contract have accumulated 6000 hours of life without significant output decrease. Similar lasers, without facet protection, have accumulated more than 10,000 hours of operating time with output decreasing gradually, as a consequence of facet erosion. A laser system has been developed, which includes thermal stabilization utilizing thermoelectric coolers and fan coooling for heat removal from the hot end of the thermoelectric module. Convection cooling for that purpose has been demonstrated to be adequate under less extreme ambients.
Author: J. P. Wittke Publisher: ISBN: Category : Languages : en Pages : 7
Book Description
A major objective of this study is the development of a package in which an injection laser is permanently bonded to a short length of a single-mode fiber, keeping both parts aligned and coupling as much optical power as possible into the single-mode fiber. Such a package had previously been developed for multimode fibers; efforts are now being made to adapt this package to the single-mode case.
Author: Hyuk-Kee Sung Publisher: ISBN: Category : Languages : en Pages : 318
Book Description
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.
Author: James P. Wittke Publisher: ISBN: Category : Languages : en Pages : 49
Book Description
Injection lasers of AlGaAs (Lambda(L) approximately 800 nm) have been permanently bonded to single-mode fibers, with power levels up to 600 microwatts being coupled into the fibers. Values over 150 microwatts were consistently obtained under cw operation at room temperature. Very close mechanical alignment tolerances are required to achieve good coupling, with positioning to + or - 1 micrometer being required. This necessitates the use of bonding materials for attaching the fiber to the laser mount that have a high dimensional stability over long time periods, and lasers whose modal patterns do not change with time or operating conditions. An epoxy provided the best bonding material that we found, although there are indications that suitable low-melting solders can also be used. Laser mode changes with drive current level can alter the observed coupling efficiency significantly.
Author: Roberto Sabella Publisher: Springer ISBN: Category : Science Languages : en Pages : 404
Book Description
High Speed Optical Communications provides a comprehensive coverage of the design and modelling of the devices and systems required for optical communication networks. It will prove to be the essential reference text for those engineers implementing and designing such networks and is one of the few works dealing with modelling and simulation of optical links at the levels both of devices and of systems. Simulation experiments and results are included, as are details of devices currently under development in research laboratories. Covers both the technical details of optical devices and their behaviour in complex systems; Includes results of applications experiments. Optical and telecommuntications scientists working in research and development and design engineers working in the field will find this text to be an indispensable resource.
Author: Rodney L. Spence Publisher: ISBN: Category : Laser communication systems Languages : en Pages : 68
Book Description
The important principles of direct- and heterodyne-detection optical free-space communications are reviewed. Signal-to-noise-ratio (SNR) and bit-error-rate (BER) expressions are derived for both the direct-detection and heterodyne-detection optical receivers. For the heterodyne system, performance degradation resulting from received-signal and local oscillator-beam misalignment and laser phase noise is analyzed. Determination of interfering background power from local and extended background sources is discussed. The BER performance of direct- and heterodyne-detection optical links in the presence of Rayleigh-distributed random pointing and tracking errors is described. Finally, several optical systems employing Nd:YAG, GaAs, and CO2 laser sources are evaluated and compared to assess their feasibility in providing high-data-rate (10- to 1000-Mbps) Mars-to-Earth communications.
Author: Publisher: ISBN: Category : Computers Languages : en Pages : 344
Book Description
The original Russian-language version was published in 1987 (Nauka House). The contributions address the generation of ultrashort light pulses by injection lasers; the application of semiconductor resonance amplifiers for the detection and communication of optical signals; GaAlAs injection laser rad
Author: Jürgen Franz Publisher: CRC Press ISBN: 9780849309359 Category : Science Languages : en Pages : 744
Book Description
The advantages of optical communications are many: ultra-high speed, highly reliable information transmission, and cost-effective modulation and transmission links to name but a few. It is no surprise that optical fiber communications systems are now in extensive use all over the world. Along with software and microelectronics, optical communication represents a key technology of modern telecommunication systems. Optical Communications: Components and Systems provides the basic material required for advanced study in theory and applications of optical fiber and space communication systems. After a review of some fundamental background material, component-based chapters discuss all relevant passive and active optical and optoelectronic components used in point-to-point links and in networks. Systems chapters address the analysis and optimization of both incoherent and coherent systems, introduce fiber optic link design, and discuss physical limits. The authors also provide an overview of applications such as optical networks and optical free-space communications. The advanced interactive multimedia communications of today and the future rely on optical fiber and space communication techniques. Optical Communications: Components and Systems offers engineers and physicists a working reference for the selection and design of optical communication systems and provides engineering students with a valuable text that prepares them for work in this essential and rapidly growing field.
Author: I. Ladany
Author: I. Ladany
Author: J. P. Wittke
Author: Hyuk-Kee Sung
Author: James P. Wittke
Author: Roberto Sabella
Author: Rodney L. Spence
Author: 
Author: Erwin K. Lau
Author: H. Kressel
Author: Jürgen Franz