The phenomenal growth in Internet traffic has lead to a huge increase in demand for data transmission capacity on a worldwide level. As a result, wavelength division multiplexing (WDM) technology emerged, which makes it possible to transmit a large number of optical channels on a single optical fiber. An equally significant development occurred in optical networks, where switching and routing of signals takes place in the optical domain. This technology places special demands on the optical sources (lasers) used in the system. This text offers a description of the optical sources (equipment and devices) designed to meet these demands. Sources for DWDM Systems is intended for the engineers and graduate students working on optical networks. There is currently a nearly explosive interest in optical networks and the components required for such networks, but there is presently no single work which covers the variety of optical sources which may be used. This book will cover a particular component, tunable lasers, which is the next "big thing" in DWDM. The primary market are engineers developing tuneable lasers for optical networks, as well as graduate students enrolled in the optical engineering curriculum, especially: optical communication, semiconductor lasers, optical networks, and/or components for optical networks.

Advances in optical fibre based communications systems have played a crucial role in the development of the information highway. By offering a single mode oscillation and narrow spectral output, distributed feedback (DFB) semiconductor laser diodes offer excellent optical light sources as well as optical filters for fibre based communications and dense wavelength division multiplexing (DWDM) systems. This comprehensive text focuses on the basic working principles of DFB laser diodes and optical filters and details the development of a new technique for enhanced system performance. Considers the optical waveguiding characteristics and properties of semiconductor materials and the physics of DFB semiconductor lasers. Presents a powerful modelling technique based on the transfer matrix method which can be used to improve the design of laser diodes, optical fibres and amplifiers. Examines the effect of the various corrugation shapes on the coupling coefficients and lasing characteristics of DFB laser diodes. Technical advice to improve immunity against the spatial hole burning effect. Extensive referencing throughout and a comprehensive glossary of symbols and abbreviations. Suitable for both introductory and advanced levels This is an indispensable textbook for undergraduate and postgraduate students of electrical and electronic engineering and physics as it consolidates their knowledge in this rapidly growing field. As a technical guide for the structural design of DFB laser diodes and optical filters, the book will serve as an invaluable reference for researchers in opto-electronics, and semi conductor device physics.

This comprehensive reference discusses the underlying physics, operational principles, and performance and applications of tunable laser diodes. The book is supplemented with practical examples and helpful notations.

This is the first book on tunable external cavity semiconductor diode lasers, providing an up-to-date survey on the physics, technology, and performance of widely applicable coherent radiation sources of tunable external cavity diode lasers. The purpose is to provide a thorough account of the state-of-the-art of tunable external cavity diode lasers which is achieved by combining this account with basic concepts of semiconductor diode lasers and its tunability with monolithic structures. The practical and accessible information in this volume will enable the reader to study external cavity diode laser, to build up the systems of external cavity diode laser as well as to develop advanced systems for their particular applications. This book will appeal to undergraduate and graduate students, scientists and engineers alike.

This book represents a unique collection of the latest developments in the rapidly developing world of semiconductor laser diode technology and applications. An international group of distinguished contributors have covered particular aspects and the book includes optimization of semiconductor laser diode parameters for fascinating applications. This collection of chapters will be of considerable interest to engineers, scientists, technologists and physicists working in research and development in the field of semiconductor laser diode, as well as to young researchers who are at the beginning of their career.

In this work, several aspects concerning (In,Al,Ga)N laser diodes with high spectral purity, designed for applications in spectroscopy, were studied. A complete fabrication process for ridgewaveguide laser diodes on GaN substrate was developed. The lateral size of the ridge waveguides was as narrow as 1.5 μm: this is necessary in order to achieve lateral single-mode lasing in (In,Al,Ga)N laser diodes. A peculiar property of (In,Al,Ga)N laser diodes is that, when the ridge is narrow, the threshold current strongly depends on the ridge etch depth. This phenomenon was investigated by fabricating laser diodes with different etch depths. For ridge widths below 2 μm, the threshold current of shallow-ridge devices was found to be more than two times larger than that of comparable deep-ridge devices. Moreover, in the lateral far-field patterns of shallow-ridge laser diodes, side-lobes were observed, which would support the hypothesis of strong index-antiguiding. The antiguiding factor at threshold was experimentally determined to be about 10, which is among the largest values ever published for (In,Al,Ga)N laser diodes. The devices were further studied by simulation, and the results confirmed that the carrier-induced index change in the quantum wells can compensate the lateral index step if the ridge is shallow. This, in turn, reduces the lateral optical confi nement, which increases the threshold current and generates side lobes in the far-fi eld patterns. Based on this research, blue and violet laser diodes suitable for packaging in TO cans and continuous-wave (CW) operation exceeding 50 mW were fabricated. An external cavity diode laser (ECDL) was also realized, which could be tuned over the spectral range 435 nm - 444 nm and provided a peak emission power of more than 27 mW CW at 439 nm. As an alternative approach to obtain a narrow spectral linewidth, the feasibility of monolithically integrated Bragg-gratings was studied.

Developed from the authors' classroom-tested material, Semiconductor Laser Theory takes a semiclassical approach to teaching the principles, structure, and applications of semiconductor lasers. Designed for graduate students in physics, electrical engineering, and materials science, the text covers many recent developments, including diode lasers u