Master's Thesis from the year 2019 in the subject Instructor Plans: Computing / Data Processing / IT / Telecommunication, , course: M.Tech, language: English, abstract: With the evolvement of high speed and long-distance data communication systems, conventional band erbium-doped fiber amplifiers (C-EDFAs) are getting more attention in recent times. Major advantage of the C-band EDFA is that it provides the user to realize a system with wide bandwidth of 40 nm. But, from the reported works, it is evident that for Gain enhancement in C-band using EDFA is reported with the use of multiple stages, multiple pumps, Gain flattening filters etc. However, these techniques suffered from high cost, complex techniques, and low performance. Here enhancement process was done through the narrowband Fiber Bragg Gratings (FBG) or fiber reflectors mirrors. In this work, a conventional band erbium doped fiber amplifier is proposed with high gain and less noise figure by incorporating the two fiber bragg gratings (FBGs) for amplified spontaneous noise reinjection. Maximum ASE is emerged at 1565 nm for the at -55 dBm carrier powers. Maximum gain is found out to be 48.16 dB with noise figure of 5.29 dBm. Fiber amplifiers are crucial and fast-growing field in the communication system. The study of this field show that the formulation procedures of lasers generation and amplifier amplification displays a problematical process due to the factors affecting and changing amplifier and laser significances in a dynamic way. Gain, noise figure, wavelength, power flatness and power output are directly affected by any element or parameter inside the amplifier configuration. The design parameters such as: erbium ions concentration, EDF length, isolators, wavelength division multiplexing (WDM) position, pump power position, circulators, pump directions, all of these elements and factors are affecting directly the amplifier output. EDFA is an amplifier that is best used because of its low loss and high gain. For communication, there are two windows 1530-1560nm(C-band) and 1560-1610nm (L-band).

Research Paper (postgraduate) from the year 2019 in the subject Instructor Plans: Computing / Data Processing / IT / Telecommunication, , course: M.Tech, language: English, abstract: Fiber amplifiers are a crucial and fast-growing field in the communication system. The study of this field show that the formulation procedures of lasers generation and amplifier amplification displays a problematical process due to the factors affecting and changing amplifier and laser significance in a dynamic way. Gain, noise figure, wavelength, power flatness and power output are directly affected by any element or parameter inside the amplifier configuration. The design parameters such as: erbium ions concentration, EDF length, isolators, wavelength division multiplexing (WDM) position, pump power position, circulators, pump directions, all of these elements and factors are affecting directly the amplifier output. EDFA is an amplifier that is best used because of its low loss and high gain. For communication, there are two windows 1530-1560nm(C-band) and 1560-1610nm (L-band).

How is light amplified in the doped fiber? How much spontaneous emission noise is generated at the output? Do detectors with optical preamplifiers outperform avalanche photodiodes? What are the current types and architectures of amplifier-based systems? These are just a handful of the essential questions answered in Erbium-Doped Fiber Amplifiers: Principles and Applications, the first book to integrate the most influential current papers on this breakthrough in fiber-optics technology. Written by one of the pioneers in the field, this unique reference has become an essential reference for telecommunication professionals. This new paperback edition provides researchers, engineers, and system designers with detailed, interdisciplinary coverage of the theoretical underpinnings, main characteristics, and primary applications of EDFAs. Packed with information on important system experiments and the best experimental results to date as well as over 1,400 references to the expanding literature. Book jacket.

This thesis is related to the spectroscopic and optical properties of doped optical fibers used as a laser amplifier for short laser pulses at high repetition rates emitting around 2 μm. Therefore short pulses created by a laser diode are amplified in thulium-doped optical fibers combining the benefits of a direct electronic control of the laser diodes' parameters and the robust setup of an optical fiber system that can easily be integrated. After the development of a high-current pulse generator especially adapted to the 2 μm laser diodes used, pulses of > 7 ns with peak powers in the Watt range could be generated. Due to the modal behaviour of these laser diodes only 2 mW of peak power could be launched into a single-mode fiber. By comparing different fiber glasses, a heavy metal fluoride glass could be identified as the optimum host for the ions thulium and holmium emitting around 2 μm. Due to the development of a numerical simulation tool based on rate equations and radiation transport equations the fiber parameters such as core diameter, fiber length etc. could be optimized, minimizing the amplified spontaneous emission (ASE) created inside the fiber. Based on this simulation a laser system consisting of cascaded fiber amplifiers could be realized. I emits short laser pulses (20-30 ns) at high repetition rates (up to 125 kHz) and peak powers of up to 5 kW. In contrast to Q-switched lasers the pulse width created is independent of the repetition rate. By using these pulses at 1.87 μm as an optical pump for a Cr2+:ZnSe laser, efficiencies of up to 22% could be reached at an emission wavelength of 2.5 μm.

With the explosion of information traffic, the role of optical amplifiers becomes very significant in fulfilling the demand of faster optical signals and data processing in the field of communication. This book covers different advanced functionalities of optical amplifiers as well as their emerging applications in optical communication networks. The first chapter deals with an efficient and validated time-domain numerical modelling of semiconductor optical amplifiers (SOAs) and SOA-based circuits, while the second chapter is based on the working of gallium nitride-based semiconductor optical amplifiers. The role of SOAs for the next generation of high-data-rate optical packet-switched network is presented in Chapter 3. Chapter 4 covers the all-optical semiconductor optical amplifier based on quantum dots (QD-SOA) and its function as an arithmetic processor. In Chapter 5, the authors have presented the role of SOAs in intensity modulation of the optical pulses and their use in deterministic timing jitter and peak pulse power equalization analysis. In Chapter 6, the investigation of broadband S-band to L-band erbium-doped fibre amplifier (EDFA) module is presented, and Chapter 7 includes the optimized design technique of Yb3+/Er3+-codoped phosphate microring resonator amplifiers. All selected chapters are very interesting and well organized, and I hope they will be of great value to postgraduate students, researchers, academics and anyone seeking to understand the advanced functionalities of optical amplifiers in the present scenario.

Optical communications networks are becoming increasingly important as there is demand for high capacity links. Dense wavelength division multiplexing (DWDM) is widely deployed at the core networks to accommodate high capacity transport systems. Optical components such as optical amplifiers, tunable filters, transceivers, termination devices and add-drop multiplexers are becoming more reliable and affordable. Access and metropolitan area networks are increasingly built with optical technologies to overcome the electronic bottleneck at network edges. New components and subsystems for very high speed optical networks offer new design options.The proceedings of the First International Conference on Optical Communications and Networks present high quality recent research results in the areas of optical communications, network components, architectures, protocols, planning, design, management and operation.